Documentation of variables for the Web100 TCP Kernel Instrumentation Set (KIS) project. Matt Mathis Jeffrey Semke Raghu Reddy John Heffner Pittsburgh Supercomputing Center Web 100 Project (c) All rights reserved. This document contains incomplete and unpublished research results. This interim version is provided only to enable developers to build an initial tool set. Future version of this document are likely to differ from this version in incompatible ways -- newer versions will completely supersede this version. Terminology: Local Host: the host from which the KIS was read Remote Host: a host that has a TCP connection between the local host and itself SNMP Data Types taken from RFC1902 "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)" ------------------------------------------------------------------------------ Restructure as (5) new tables: Perf, Path, Stack, App, Tune ------------------------------------------------------------------------------ CATEGORY: Performance CatDescr: All basic performance instrumentation or native state variables SNMPprefix: tcpEStatsPerf SNMPfile: 1Aperf SNMPfile: 1Bperf 30 ------------------------------------------------------------------------------ CATEGORY: Path CatDescr: Detailed path statistics SNMPprefix: tcpEStatsPath SNMPfile: 2Apath SNMPfile: 2Bpath 20 ------------------------------------------------------------------------------ CATEGORY: Stack CatDescr: Stack Internal algorithms - how well coping w/the path SNMPprefix: tcpEStatsStack SNMPfile: 3Astack SNMPfile: 3Bstack 20 ------------------------------------------------------------------------------ CATEGORY: Application CatDescr: How well is the application staying ahead of TCP SNMPprefix: tcpEStatsApp SNMPfile: 4Aapp SNMPfile: 4Bapp 20 ------------------------------------------------------------------------------ CATEGORY: Tune CatDescr: Manual Tuning controls to facilitate workarounds for path problems SNMPprefix: tcpEStatsTune SNMPfile: 5Atune SNMPfile: 5Btune ------------------------------------------------------------------------------ CATEGORY: CONNECTION ID CatDescr: The 5 tuple that uniquely identifies every connection. See [RFC793]. ------------------------------------------------------------------------------ VariableName: protocol Scope: standard ShortDescr: Protocol type for this connection ProcType: Integer32 Description: Protocol type for this connection. R/W: read-only ------------------------------------------------------------------------------ VariableName: LocalAddress Scope: standard ShortDescr: Local IP Address ProcType: Ip_Address Description: IP Address of the host from which the KIS was read. R/W: read-only ------------------------------------------------------------------------------ VariableName: LocalAddressType Scope: standard ShortDescr: Local Address Type ProcType: Integer Description: The address type of tcpEStatsConnectLocalAddress. Only ipv4(1) and ipv6(2) are expected. R/W: read-only ------------------------------------------------------------------------------ VariableName: LocalPort Scope: standard ShortDescr: Local Port Number ProcType: Unsigned16 Description: The Local Host's TCP port number for a connection. R/W: read-only ------------------------------------------------------------------------------ VariableName: RemAddress Scope: standard RenameFrom: RemoteAddress ShortDescr: Remote IP Address ProcType: Ip_Address Description: IP Address of the Remote host's end of a connection. R/W: read-only ------------------------------------------------------------------------------ VariableName: RemPort Scope: standard RenameFrom: RemotePort ShortDescr: Remote Port Number ProcType: Unsigned16 Description: The Remote Host's TCP port number for a connection. R/W: read-only ------------------------------------------------------------------------------ CATEGORY: WAD CatDescr: Work Around Daemon for the Net100 project. These controls are not safe for general use. ------------------------------------------------------------------------------ VariableName: WAD_IFQ Scope: internal ShortDescr: Disable enter_cwr when IF queue is full ProcType: Gauge32 Description: Disable enter_cwr when IF queue is full R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_MaxBurst Scope: internal ShortDescr: Allow bursts when cwnd is greater than awnd ProcType: Gauge32 Description: Cwnd is limited to WAD_MaxBurst above the actual window. Set it very large if you want no burst suppression. The system default is 3. R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_MaxSsthresh Scope: internal ShortDescr: Floyd modified slowstart ProcType: Gauge32 Description: Floyd modified slowstart R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_FloydAIMD Scope: internal ShortDescr: Floyd modified TCP for long fat networks ProcType: Gauge32 Description: Floyd modified TCP for long fat networks R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_AI Scope: internal ShortDescr: Set additive increase in units of 1/8 MSS ProcType: Gauge32 Description: Set additive increase in units of 1/8 MSS R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_MD Scope: internal ShortDescr: Set multiplicative decrease ProcType: Gauge32 Description: Set multiplicative decrease R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_NoAI Scope: internal ShortDescr: Disable the Additive Increase ProcType: Integer Description: Disable the Additive Increase R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_CwndAdjust Scope: internal ShortDescr: Adjust Cwnd once by the given delta (segments) ProcType: Integer32 Description: Adjust Cwnd once by the given delta (segments). R/W: read-write ------------------------------------------------------------------------------ #ifdef WEB100_PRIVATE VariableName: WAD_BurstSize Scope: new ShortDescr: Cause the output queue to be bursty ProcType: Gauge32 Description: Cause the output queue to be bursty R/W: read-write ------------------------------------------------------------------------------ VariableName: WAD_Delay Scope: new ShortDescr: Delay output segments to emulate a long path ProcType: Gauge32 Description: Delay output segments to emulate a long path R/W: read-write ------------------------------------------------------------------------------ VariableName: X_FullBursts Scope: new ShortDescr: Number of successful WAD_BurstSize bursts ProcType: ZeroBasedCounter32 Description: R/W: read-only ------------------------------------------------------------------------------ VariableName: X_PushedBursts Scope: new ShortDescr: Number of bursts sent before reaching WAD_BurstSize ProcType: ZeroBasedCounter32 Description: R/W: read-only ------------------------------------------------------------------------------ #endif /* WEB100_PRIVATE */ SNMPcomment: 3Astack The following objects indicate TCP state and if various optional TCP features or algorithms are enabled. ------------------------------------------------------------------------------ VariableName: State Scope: standard ShortDescr: TCP State Table: 3Astack . ProcType: INTEGER Description: An integer value representing the connection state from the TCP State Transition Diagram. See [RFC793]. The value listen(2) is included only for parallelism to the old tcpConnTable, and should not be used because the listen state in managed by the tcpListenerTable. The value DeleteTcb(12) is included only for parallelism to the tcpConnTable mechanism for terminating connections, although this table does not permit writing. R/W: read-only PossibleValues: tcpESStateClosed(1) tcpESStateListen(2) tcpESStateSynSent(3) tcpESStateSynReceived(4) tcpESStateEstablished(5) tcpESStateFinWait1(6) tcpESStateFinWait2(7) tcpESStateCloseWait(8) tcpESStateLastAck(9) tcpESStateClosing(10) tcpESStateTimeWait(11) tcpESStateDeleteTcb(12) ------------------------------------------------------------------------------ VariableName: SACK Scope: standard RenameFrom: SACKEnabled ShortDescr: SACK Enabled Table: 3Astack . ProcType: TruthValue Description: True(1) if SACK has been negotiated on, else false(2). See [RFC2018]. R/W: read-only ------------------------------------------------------------------------------ VariableName: TimeStamps Scope: standard RenameFrom: TimestampsEnabled ShortDescr: Timestamps Enabled Table: 3Astack . ProcType: TruthValue Description: True(1) if timestamps have been negotiated on, else false(2). See [RFC1323]. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECN Scope: standard RenameFrom: ECNEnabled ShortDescr: Explicit Congestion Notification is Enabled Table: 3Astack . ProcType: TruthValue Description: True(1) if ECN has been negotiated on, else false(2). See [RFC3168]. R/W: read-only ------------------------------------------------------------------------------ VariableName: Nagle Scope: standard RenameFrom: NagleEnabled ShortDescr: Nagle Algorithm Enabled Table: 3Astack . ProcType: TruthValue Description: True(1) if the Nagle algorithm is being used, else false(2). See [RFC896] and [RFC1122]. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndWindScale Scope: standard RenameFrom: SndWinScale ShortDescr: Window scale used by the sender to decode snd.wnd Table: 3Astack . ProcType: Integer32 Description: The value of Snd.Wind.Scale from [RFC1323]. Note that tcpEStatsStackSndWindScale is either zero or the same as tcpEStatsStackWinScaleRcvd. R/W: read-only ------------------------------------------------------------------------------ VariableName: RcvWindScale Scope: standard RenameFrom: RcvWinScale ShortDescr: Window scale used by the receiver to encode seg.wnd Table: 3Astack . ProcType: Integer32 Description: The value of Rcv.Wind.Scale from [RFC1323]. Note that tcpEStatsStackRcvWindScale is either zero or the same as tcpEStatsStackWinScaleSent. R/W: read-only ------------------------------------------------------------------------------ VariableName: ActiveOpen Scope: standard ShortDescr: True if local host was the one that sent the SYN. Table: 3Astack + ProcType: TruthValue Description: True(1) if the local connection traversed the SYN-SENT state, else false(2). See [RFC793]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional objects reflect the options requested on the SYN and/or SYN-ACK. These are useful for debugging problems with TCP option negotiation. ------------------------------------------------------------------------------ VariableName: MSSSent Scope: standard ShortDescr: Mss Option sent Table: 3Bstack + ProcType: Unsigned32 Description: The value sent in an MSS option, or zero if none. R/W: read-only ------------------------------------------------------------------------------ VariableName: MSSRcvd Scope: standard ShortDescr: MSS Option received Table: 3Bstack + ProcType: Unsigned32 Description: The value received in an MSS option, or zero if none. R/W: read-only ------------------------------------------------------------------------------ VariableName: WinScaleSent Scope: standard # RenameFrom: SendWinScale ShortDescr: Requested Window Scale Out Table: 3Bstack + ProcType: Integer32 PossibleValues: (-1..14) Description: The value of the transmitted window scale option if one was sent; otherwise, a value of -1. See [RFC1323]. R/W: read-only ------------------------------------------------------------------------------ VariableName: WinScaleRcvd Scope: standard # RenameFrom: RecvWinScale ShortDescr: requested window scale Table: 3Bstack + ProcType: Integer32 PossibleValues: (-1..14) Description: The value of the received window scale option if one was received; otherwise, a value of -1. See [RFC1323]. R/W: read-only ------------------------------------------------------------------------------ VariableName: SACKokSent Scope: standard ShortDescr: SACKok was sent in SYN or SYN-ACK Table: 3Bstack + ProcType: TruthValue Description: True(1) if SACKok option was sent, else false(2). See [RFC2018]. R/W: read-only ------------------------------------------------------------------------------ VariableName: SACKokRcvd Scope: standard ShortDescr: SACKok was seen in SYN or SYN-ACK Table: 3Bstack + ProcType: TruthValue Description: True(1) if SACKok option was received, else false(2). See [RFC2018]. R/W: read-only ------------------------------------------------------------------------------ VariableName: TimeStampSent Scope: standard ShortDescr: Timestamp sent in SYN or SYN-ACK Table: 3Bstack + ProcType: TruthValue Description: True(1) if Timestamp option was sent, else false(2). See [RFC1323]. R/W: read-only ------------------------------------------------------------------------------ VariableName: TimeStampRcvd Scope: standard ShortDescr: Timestamp received in SYN or SYN-ACK Table: 3Bstack + ProcType: TruthValue Description: True(1) if Timestamp option was received, else false(2). See [RFC1323]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 1Aperf The following objects provide statistics on aggregate segments and data sent on a connection. These provide a direct measure of the Internet capacity consumed by a connection. ------------------------------------------------------------------------------ VariableName: SegsOut RenameFrom: PktsOut Scope: standard ShortDescr: Total Segments Out Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The total number of segments sent. R/W: read-only ------------------------------------------------------------------------------ VariableName: DataSegsOut RenameFrom: DataPktsOut Scope: standard ShortDescr: Data Segments Out Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of segments sent containing a positive length data segment. R/W: read-only ------------------------------------------------------------------------------ VariableName: DataOctetsOut RenameFrom: DataBytesOut Scope: standard ShortDescr: Data Octets Out Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of octets of data contained in transmitted segments, including retransmitted data. Note that this does not include TCP headers. R/W: read-only ------------------------------------------------------------------------------ VariableName: HCDataOctetsOut Scope: standard ShortDescr: Data Octets Out Table: 1Aperf + ProcType: ZeroBasedCounter64 Description: The number of octets of data contained in transmitted segments, including retransmitted data, on systems that can transmit more than 10 million bits per second. Note that this does not include TCP headers. R/W: read-only ------------------------------------------------------------------------------ VariableName: SegsRetrans RenameFrom: PktsRetrans Scope: standard ShortDescr: Segments With Retransmitted Data Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of segments transmitted containing at least some retransmitted data. R/W: read-only ------------------------------------------------------------------------------ VariableName: OctetsRetrans RenameFrom: BytesRetrans Scope: standard ShortDescr: Retransmitted Octets Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of octets retransmitted. R/W: read-only ------------------------------------------------------------------------------ VariableName: SegsIn RenameFrom: PktsIn Scope: standard ShortDescr: Total Segments In Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The total number of segments received. R/W: read-only ------------------------------------------------------------------------------ VariableName: DataSegsIn RenameFrom: DataPktsIn Scope: standard ShortDescr: Total Data Segments In Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of segments received containing a positive length data segment. R/W: read-only ------------------------------------------------------------------------------ VariableName: DataOctetsIn RenameFrom: DataBytesIn Scope: standard ShortDescr: Data Octets In Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of octets contained in received data segments, including retransmitted data. Note that this does not include TCP headers. R/W: read-only ------------------------------------------------------------------------------ VariableName: HCDataOctetsIn Scope: standard ShortDescr: Data Octets In Table: 1Aperf + ProcType: ZeroBasedCounter64 Description: The number of octets contained in received data segments, including retransmitted data, on systems that can receive more than 10 million bits per second. Note that this does not include TCP headers. R/W: read-only ------------------------------------------------------------------------------ VariableName: ElapsedSecs RenameFrom: Duration Scope: standard RenameFrom: CurrTime ShortDescr: Elapsed seconds Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The seconds part of the time elapsed between tcpEStatsPerfStartTimeStamp and the most recent protocol event (segment sent or received). R/W: read-only ------------------------------------------------------------------------------ VariableName: ElapsedMicroSecs Scope: standard ShortDescr: Elapsed micro Seconds Table: 1Aperf > ProcType: ZeroBasedCounter32 Description: The micro-second part of time elapsed between tcpEStatsPerfStartTimeStamp to the most recent protocol event (segment sent or received). This may be updated in what ever time granularity is the system supports. R/W: read-only ------------------------------------------------------------------------------ VariableName: StartTimeStamp Scope: standard RenameFrom: StartTimeSec StartTime StartTimeUsec ShortDescr: Start Time Table: 1Aperf . ProcType: Integer32 SNMPType: DateAndTime Description: Time at which this row was created and all ZeroBasedCounters in the row were initialized to zero. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 1Aperf The following objects can be used to fit minimal performance models to the TCP data rate. ------------------------------------------------------------------------------ VariableName: CurMSS Scope: standard RenameFrom: CurrentMSS ShortDescr: Current Maximum Segment Size Table: 1Aperf . ProcType: Gauge32 Description: The current maximum segment size (MSS), in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: PipeSize Scope: standard ShortDescr: Octets in flight Table: 1Aperf + ProcType: Gauge32 Description: The TCP senders current estimate of the number of unacknowledged data octets in the network. While not in recovery, this is the same as ``Flight Size'' as defined in RFC2581. While in recovery, this is the same as ``pipe'' as defined in RFC3517. If RFC3517 is not in effect, the data octets in flight can be estimated as SND.NXT minus SND.UNA plus any retransmitted data, minus some measure of the data that has left the network. For example, with Reno or NewReno style TCP, the number of duplicate acknowledgement is used to count the number of segments that have left the network. I.e.: PipeSize=SND.NXT-SND.UNA+(retransmits-dupacks)*CurMSS R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxPipeSize Scope: standard ShortDescr: Max Octets in flight Table: 1Aperf + ProcType: Gauge32 Description: The maximum value of tcpEStatsPerfPipeSize, for this connection. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 2Bpath The following optional objects instrument the round trip time estimator and the retransmission timeout timer. See [RFC2988]. ------------------------------------------------------------------------------ VariableName: SampleRTT Scope: standard RenameFrom: SampledRTT ShortDescr: Most recent RTT sample Table: 2Bpath + ProcType: Gauge32 Description: The most recent raw round trip time measurement, in milliseconds, used in calculation of the RTO. R/W: read-only ------------------------------------------------------------------------------ VariableName: SmoothedRTT Scope: standard ShortDescr: Smoothed RTT Table: 1Aperf . ProcType: Gauge32 Description: The smoothed round trip time, in milliseconds, used in calculation of the RTO. See SRTT in [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: RTTVar Scope: standard ShortDescr: RTT variation Table: 2Bpath . ProcType: Gauge32 Description: The round trip time variation, in milliseconds, used in calculation of the RTO. See RTTVAR in [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxRTT Scope: standard ShortDescr: Maximum RTT Table: 2Bpath + ProcType: Gauge32 Description: The maximum sampled round trip time, in milliseconds. R/W: read-only ------------------------------------------------------------------------------ VariableName: MinRTT Scope: standard ShortDescr: Minimum RTT Table: 2Bpath + ProcType: Gauge32 Description: The minimum sampled round trip time, in milliseconds. R/W: read-only ------------------------------------------------------------------------------ VariableName: SumRTT Scope: standard ShortDescr: Cumulative RTT Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The sum of all sampled round trip times, in milliseconds. Note that the change in tcpEStatsPathSumRTT divided by the change in tcpEStatsPathCountRTT is the mean RTT, uniformly averaged over an enter interval. R/W: read-only ------------------------------------------------------------------------------ VariableName: HCSumRTT Scope: standard ShortDescr: Cumulative RTT Table: 2Bpath + ProcType: ZeroBasedCounter64 Description: The sum of all sampled round trip times, in milliseconds, on all systems that implement multiple concurrent RTT measurements. Note that the change in tcpEStatsPathHCSumRTT divided by the change in tcpEStatsPathCountRTT is the mean RTT, uniformly averaged over an enter interval. R/W: read-only ------------------------------------------------------------------------------ VariableName: CountRTT Scope: standard ShortDescr: Count of samples in SumRTT Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of round trip time samples included in tcpEStatsPathSumRTT. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurRTO Scope: standard RenameFrom: CurrentRTO ShortDescr: Current Retransmission Timer Table: 1Aperf . ProcType: Gauge32 Description: The current value of the retransmit timer RTO, in milliseconds. See [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxRTO Scope: standard ShortDescr: Maximum Retransmission Timer Table: 2Bpath + ProcType: Gauge32 Description: The maximum value of the retransmit timer RTO, in milliseconds. See [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MinRTO Scope: standard ShortDescr: Minimum Retransmission Timer Table: 2Bpath + ProcType: Gauge32 Description: The minimum value of the retransmit timer RTO, in milliseconds. See [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional objects instrument unusual protocol events that probably indicate implementation problems in the protocol or path. ------------------------------------------------------------------------------ VariableName: SoftErrors Scope: standard ShortDescr: Soft Errors Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of segments that fail various consistency tests during TCP input processing. Soft errors might cause the segment to be discard but some do not. Some of these soft errors cause the generation of a TCP acknowledgment, others are silently discarded. R/W: read-only ------------------------------------------------------------------------------ VariableName: SoftErrorReason Scope: standard ShortDescr: Identifies the consistency test that most recently failed Table: 3Bstack > ProcType: INTEGER R/W: read-only PossibleValues: belowDataWindow(1) aboveDataWindow(2) belowAckWindow(3) aboveAckWindow(4) belowTSWindow(5) aboveTSWindow(6) dataCheckSum(7) otherSoftError(8) Description: This object identities which consistency test most recently failed during tcp input processing. This object should be set every time tcpEStatsStackSoftErrors is incremented. The codes are as follows: belowDataWindow - All data in the segment is below SND.UNA. (Normal for keep-alives and possibly zero window probes). aboveDataWindow - Some data in the segment is above SND.WND. (Indicates an implementation bug or serious fraud). belowAckWindow - ACK below SND.UNA. (Indicates that the return path is reordering ACKs) aboveAckWindow - An ACK for data that we have not sent. (Indicates an implementation bug or serious fraud). belowTSWindow - TSecr on the segment is older than the current TS.Recent [RFC1323] (Normal for the rare case where PAWS detects data reordered by the network.) aboveTSWindow - TSecr on the segment is newer than the current TS.Recent [RFC1323]. (Indicates an implementation bug or serious fraud). dataCheckSum - Incorrect checksum. Note that this value is intrinsically fragile, because the header fields used to identify the connection may have been corrupted. otherSoftError - All other soft errors. Implementors are permitted to assign additional codes greater than 8 such that all SoftErrors in their implementation have unique codes. Management stations are to accumulate all unassigned codes as "otherSoftErrors" ------------------------------------------------------------------------------ SNMPcomment: 2Bpath The following optional objects provide information about how TCP is using the IP layer. ------------------------------------------------------------------------------ VariableName: IpTtl Scope: standard ShortDescr: TTL on the incoming segment Table: 2Bpath + ProcType: Integer32 Description: The value of the TTL field carried in the most recently received IP header. This is sometimes useful to detect changing or unstable routes. R/W: read-only ------------------------------------------------------------------------------ VariableName: IpTosIn RenameFrom: IpDscp Scope: standard ShortDescr: The DSCP field of the incoming segment. Table: 2Bpath + ProcType: Integer32 Description: The value of the IPv4 Type Of Service octet, or the IPv6 traffic class octet, carried in the most recently received IP header. See [RFC2474] and [RFC3260]. This is useful to diagnose interactions between TCP and any IP layer packet scheduling and delivery policy, which might be in effect to implement QoS. R/W: read-only ------------------------------------------------------------------------------ VariableName: IpTosOut Scope: standard ShortDescr: The DSCP field of the incoming segment. Table: 2Bpath . ProcType: Integer32 Description: The value of the IPv4 Type Of Service octet, or the IPv6 traffic class octet, carried in the most recently transmitted IP header. See [RFC2474] and [RFC3260]. This is useful to diagnose interactions between TCP and any IP layer packet scheduling and delivery policy, which might be in effect to implement QoS. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 4Aapp The following objects provide throughput statistics for the connection including sequence numbers and elapsed application data. These permit direct observation of the applications progress, in terms of elapsed data delivery and elapsed time. See [RFC793]. ------------------------------------------------------------------------------ VariableName: SndUna Scope: standard RenameFrom: snd_una ShortDescr: Oldest Unacknowledged Sequence Number. Table: 4Aapp . ProcType: Counter32 Description: The value of SND.UNA, the oldest unacknowledged sequence number. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndNxt Scope: standard RenameFrom: snd_nxt ShortDescr: Next Sequence Number to be Sent Table: 4Aapp . ProcType: Integer32 Description: The value of SND.NXT, the next sequence number to be sent. Note that tcpEStatsAppSndNxt is not a monotonic (and thus not a counter) because TCP sometimes retransmits lost data by pulling tcpEStatsAppSndNxt back to the missing data. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndMax Scope: standard RenameFrom: snd_max ShortDescr: Maximum Value of snd_nxt Table: 4Aapp . ProcType: Counter32 Description: The farthest forward (right most or largest) SND.NXT value. Note that this will be equal to tcpEStatsAppSndNxt except when tcpEStatsAppSndNxt is pulled back during recovery. R/W: read-only ------------------------------------------------------------------------------ VariableName: ThruOctetsAcked RenameFrom: ThruBytesAcked Scope: standard ShortDescr: Total throughput octets sent Table: 4Aapp + ProcType: ZeroBasedCounter32 Description: The number of octets for which cumulative acknowledgments have been received. Note that this will be the sum of changes to tcpEStatsAppSndUna. R/W: read-only ------------------------------------------------------------------------------ VariableName: HCThruOctetsAcked Scope: standard ShortDescr: Total throughput octets sent Table: 4Aapp + ProcType: ZeroBasedCounter64 Description: The number of octets for which cumulative acknowledgments have been received, on systems that can receive more than 10 million bits per second. Note that this will be the sum of changes in tcpEStatsAppSndUna. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional initial value objects are useful for conformance testing instruments on application progress and consumed network resources. ------------------------------------------------------------------------------ VariableName: SndInitial Scope: standard RenameFrom: SndISS ShortDescr: Initial send sequence number. Table: 3Bstack + ProcType: Counter32 Description: Initial send sequence number. Note that by definition tcpEStatsStackSndInitial never changes for a given connection. See [RFC793]. R/W: read-only ------------------------------------------------------------------------------ VariableName: RcvNxt Scope: standard RenameFrom: rcv_nxt ShortDescr: Next sequence number expected on an incoming segment Table: 4Aapp . ProcType: Counter32 Description: The value of RCV.NXT from [RFC793]. The next sequence number expected on an incoming segment, and the left or lower edge of the receive window. R/W: read-only ------------------------------------------------------------------------------ VariableName: ThruOctetsReceived RenameFrom: ThruBytesReceived Scope: standard ShortDescr: Total throughput octets received Table: 4Aapp + ProcType: ZeroBasedCounter32 Description: The number of octets for which cumulative acknowledgments have been sent. Note that this will be the sum of changes to tcpEStatsAppRcvNxt. R/W: read-only ------------------------------------------------------------------------------ VariableName: HCThruOctetsReceived Scope: standard ShortDescr: Total throughput octets received Table: 4Aapp + ProcType: ZeroBasedCounter64 Description: The number of octets for which cumulative acknowledgments have been sent, on systems that can transmit more than 10 million bits per second. Note that this will be the sum of changes in tcpEStatsAppRcvNxt. R/W: read-only ------------------------------------------------------------------------------ VariableName: RecInitial Scope: standard RenameFrom: RecvISS ShortDescr: Initial receive sequence number Table: 3Bstack + ProcType: Counter32 Description: Initial receive sequence number. Note that by definition tcpEStatsStackRecInitial never changes for a given connection. See [RFC793]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 1Bperf The following optional objects can be used to quickly identify which subsystems are limiting TCP performance. There are three parallel pairs of instruments that measure the extent to which TCP performance is limited by the announced receiver window (indicating a receiver bottleneck), the current congestion window or retransmission timeout (indicating a path bottleneck) and all others events (indicating a sender bottleneck). These instruments should be updated every time the TCP output routine stops sending data. The elapsed time since the previous stop is accumulated into the appropriate object as determined by the previous stop reason (e.g. stop state). The current stop reason determines which timer will be updated the next time TCP output stops. Since there is no explicit stop at the beginning of a timeout, it is necessary to retroactively reclassify the previous stop as "Congestion Limited". ------------------------------------------------------------------------------ VariableName: SndLimTransRwin Scope: standard ShortDescr: Receiver Limited Transitions Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The number of transitions into the "Receiver Limited" state from either the "Congestion Limited" or "Sender Limited" states. This state is entered whenever TCP transmission stops because the sender has filled the announced receiver window. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndLimTransCwnd Scope: standard ShortDescr: Congestion Limited Transitions Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The number of transitions into the "Congestion Limited" state from either the "Receiver Limited" or "Sender Limited" states. This state is entered whenever TCP transmission stops because the sender has reached some limit defined by congestion control (e.g. cwnd) or other algorithms (retransmission timeouts) designed to control network traffic. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndLimTransSnd Scope: standard RenameFrom: SndLimTransSender ShortDescr: Sender Limited Transitions Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The number of transitions into the "Sender Limited" state from either the "Receiver Limited" or "Congestion Limited" states. This state is entered whenever TCP transmission stops due to some sender limit such as running out of application data or other resources and the Karn algorithm. When TCP stops sending data for any reason which can not be classified as Receiver Limited or Congestion Limited it must be treated as Sender Limited. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndLimTimeRwin Scope: standard ShortDescr: Receiver Limited Time Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The cumulative time (in milliseconds) spent in the "Receiver Limited" state. See tcpEStatsPerfSndLimTransRwin. R/W: read-only ------------------------------------------------------------------------------ VariableName: SndLimTimeCwnd Scope: standard ShortDescr: Congestion Limited Time Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The cumulative time (in milliseconds) spent in the "Congestion Limited" state. See tcpEStatsPerfSndLimTransCwnd. When there is a retransmission timeout, it should be counted in tcpEStatsPerfSndLimTimeCwnd (and not the cumulative time for some other state.) R/W: read-only ------------------------------------------------------------------------------ VariableName: SndLimTimeSnd Scope: standard RenameFrom: SndLimTimeSender ShortDescr: Sender Limited Time Table: 1Bperf > ProcType: ZeroBasedCounter32 Description: The cumulative time (in milliseconds) spent in the "Sender Limited" state. See tcpEStatsPerfSndLimTransSnd. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Astack The following objects instrument the overall operation of TCP congestion control and data retransmissions. These instruments are sufficient to fit the actual performance to an updated macroscopic performance model [RFC2581] [Mat97] [Pad98]. ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional objects expose the detailed operation of the congestion control algorithms. ------------------------------------------------------------------------------ VariableName: SlowStart Scope: standard ShortDescr: Slow Start Window Opens Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of times the congestion window has been increased by the Slow Start algorithm. See [RFC2581]. R/W: read-only ------------------------------------------------------------------------------ VariableName: CongAvoid Scope: standard ShortDescr: Congestion Avoidance Window Opens Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of times the congestion window has been increased by the Congestion Avoidance algorithm. See [RFC2581]. R/W: read-only ------------------------------------------------------------------------------ VariableName: CongSignals Scope: standard RenameFrom: CongestionSignals RenameFrom: Recoveries PreCongCountRTT ShortDescr: Total Congestion Signals. Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of multiplicative downward congestion window adjustments due to all forms of congestion signals, including Fast Retransmit, ECN and timeouts. This object summarizes all events that invoke the MD portion of AIMD congestion control, and as such is the best indicator of how cwnd is being affected by congestion. Note that retransmission timeouts multiplicatively reduce the window implicitly by setting ssthresh, and should be included in tcpEStatsPerfCongSignals. In order to minimize spurious congestion indications due to out-of-order segments, tcpEStatsPerfCongSignals should be incremented in association with the Fast Retransmit algorithm. R/W: read-only ------------------------------------------------------------------------------ VariableName: OtherReductions Scope: standard ShortDescr: Other Congestion Window Reductions Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of congestion window reductions made as a result of anything other than AIMD congestion control algorithms. Examples of non-multiplicative window reductions include experimental algorithms such as Vegas [Bra94], and Congestion Window Validation [RFC2861]. All window reductions MUST be counted as either tcpEStatsPerfCongSignals or tcpEStatsStackOtherReductions. R/W: read-only ------------------------------------------------------------------------------ VariableName: CongOverCount Scope: standard RenameFrom: CongestionOverCount ShortDescr: Overcounted congestion Signals Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of congestion events which were 'backed out' of the congestion control state machine such that the congestion window was restored to a prior value. This can happen due to the Eiffle algorithm [RFC3522] or other algorithms which can be used to detect and cancel spurious invocations of the Fast Retransmit Algorithm. Although it may be feasible to undo the effects of spurious invocation of the Fast Retransmit congestion events can not easily be backed out of tcpEStatsPerfCongSignals and tcpEStatsPathPreCongSumCwnd, etc. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurCwnd Scope: standard RenameFrom: CurrentCwnd ShortDescr: Current Congestion Window Table: 1Aperf . ProcType: Gauge32 Description: The current congestion window, in octets. See [RFC2581]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxSsCwnd Scope: standard RenameFrom: MaxCwnd ShortDescr: Maximum SS Congestion Window Table: 3Astack + ProcType: Gauge32 Description: The maximum congestion window used during Slow Start, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxCaCwnd Scope: standard ShortDescr: Maximum CA Congestion Window Table: 3Astack + ProcType: Gauge32 Description: The maximum congestion window used during Congestion Avoidance, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: LimCwnd Scope: standard ShortDescr: Maximum Congestion Window Table: 5Btune + ProcType: Gauge32 Description: A control to set the maximum congestion window which may be used, in octets. R/W: read-write ------------------------------------------------------------------------------ VariableName: CurSsthresh Scope: standard RenameFrom: CurrentSsthresh ShortDescr: Current Slowstart Threshold Table: 1Aperf . ProcType: Gauge32 Description: The current slow start threshold in octets. See [RFC2581]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxSsthresh Scope: standard ShortDescr: Maximum Slowstart Threshold Table: 3Astack + ProcType: Gauge32 Description: The maximum slow start threshold, excluding the initial value. R/W: read-only ------------------------------------------------------------------------------ VariableName: MinSsthresh Scope: standard ShortDescr: Minimum Slowstart Threshold Table: 3Astack + ProcType: Gauge32 Description: The minimum slow start threshold. R/W: read-only ------------------------------------------------------------------------------ VariableName: LimSsthresh Scope: standard ShortDescr: Maximum Slowstart Threshhold Table: 5Btune + ProcType: Gauge32 Description: A control to limit the maximum queue space (in octets) that this TCP connection is likely to occupy during slowstart. It can be implemented with the algorithm described in RFC3742 by setting the max_ssthresh parameter to twice tcpEStatsTuneLimSsthresh. This algorithm can be used to overcome some TCP performance problems over network paths that do not have sufficient buffering to withstand the bursts normally present during slowstart. R/W: read-write ------------------------------------------------------------------------------ VariableName: InRecovery Scope: standard ShortDescr: Recovery state Table: 3Astack . ProcType: INTEGER Description: An integer value representing the state of the loss recovery for this connection. tcpESDataContiguous(1) indicates that the remote receiver is reporting contiguous data (no duplicate acknowledgments or SACK options) and that there are no unacknowledged retransmissions. tcpESDataUnordered(2) indicates that the remote receiver is reporting missing or out-of-order data (sending duplicate acknowledgments or SACK options) and that there are no unacknowledged retransmissions (because the missing data has not yet been retransmitted). tcpESDataRecovery(3) indicates that the sender has outstanding retransmitted data which is still in flight (i.e. is still unacknowledged). tcpEStatsStackInRecovery is a required precondition for some algorithms on other instruments. E.g. Some algorithms to estimate path properties may not be valid during recovery. R/W: read-only PossibleValues: tcpESDataContiguous(1) tcpESDataUnordered(2) tcpESDataRecovery(3) ------------------------------------------------------------------------------ VariableName: FastRetran Scope: standard ShortDescr: Fast Retransmits Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of invocations of the Fast Retransmit algorithm. See [RFC2581]. R/W: read-only ------------------------------------------------------------------------------ VariableName: Timeouts Scope: standard ShortDescr: Number of Initial Timeouts Table: 1Aperf + ProcType: ZeroBasedCounter32 Description: The number of times the retransmit timeout has expired when the RTO backoff multiplier is equal to one. See [RFC2988]. R/W: read-only. ------------------------------------------------------------------------------ VariableName: SubsequentTimeouts Scope: standard ShortDescr: Subsequent (repeated) Timeouts Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of times the retransmit timeout has expired after the RTO has been doubled. See 5.5 of [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurTimeoutCount Scope: standard RenameFrom: CurrTimeoutCount ShortDescr: Current Repeated Timeout Count Table: 3Bstack + ProcType: Gauge32 Description: The current number of times the retransmit timeout has expired without receiving an acknowledgment for new data. tcpEStatsStackCurTimeoutCount is reset to zero when new data is acknowledged and incremented for each invocation of section 5.5 in [RFC2988]. R/W: read-only ------------------------------------------------------------------------------ VariableName: AbruptTimeouts Scope: standard ShortDescr: Abrupt Timeouts Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of timeouts that occurred without any immediately preceding duplicate acknowledgments or other indications of congestion. Abrupt Timeouts indicate that the path lost an entire window of data or acknowledgments. Timeouts that are preceded by duplicate acknowledgments or other congestion signals (e.g. ECN) are not counted as abrupt, and might have been avoided by a more sophisticated Fast Retransmit algorithm. R/W: read-only ------------------------------------------------------------------------------ VariableName: DupAcksIn Scope: standard ShortDescr: Number of Duplicate ACKs Received Table: 3Astack + ProcType: ZeroBasedCounter32 Description: The number of duplicate ACKs received. R/W: read-only ------------------------------------------------------------------------------ VariableName: SACKsRcvd Scope: standard ShortDescr: Number of SACKs Options Received Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of SACK options received. See [RFC2018]. R/W: read-only ------------------------------------------------------------------------------ VariableName: SACKBlocksRcvd Scope: standard ShortDescr: Number of SACKs blocks Received Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of SACK blocks received (within SACK options). R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 2Bpath The following optional objects characterize the congestion feedback signals by collecting statistics on how the congestion events are correlated to losses, changes in RTT and other protocol events. ------------------------------------------------------------------------------ VariableName: PreCongSumCwnd Scope: standard RenameFrom: SumCwndAtCong ShortDescr: Sum Congestion Window at Congestion Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The sum of the values of the congestion window, in octets, captured each time a congestion signal is received. This MUST be updated each time tcpEStatsPerfCongSignals is incremented, such that the ratio is the average window at congestion. R/W: read-only ------------------------------------------------------------------------------ VariableName: PreCongSumRTT Scope: standard ShortDescr: Sum of the RTT as measured just before congestion. Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: Sum of the last sample of the RTT (tcpEStatsPathSampleRTT) prior to received congestion signals. This MUST be updated each time tcpEStatsPerfCongSignals is incremented, such that the ratio is the average RTT just prior to congestion. R/W: read-only ------------------------------------------------------------------------------ VariableName: PostCongSumRTT Scope: standard ShortDescr: Sum of the RTT as measured just after congestion. Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: Sum of the first RTT sample following a received congestion signal. R/W: read-only ------------------------------------------------------------------------------ VariableName: PostCongCountRTT Scope: standard ShortDescr: Count of the RTT as measured just after congestion Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of RTT samples included in tcpEStatsPathPostCongSumRTT such that the ratio is average RTT just after congestion. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 2Bpath The following optional objects can be used to detect other types of non-loss congestion signals such as source quench or ECN. ------------------------------------------------------------------------------ VariableName: ECNsignals Scope: standard ShortDescr: All ECN congestion signals Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of congestion signals delivered via all forms of explicit congestion notification including the ECE bit and failing the ECN nonce check, etc. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECERcvd Scope: standard ShortDescr: ECE congestions signals Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of congestion signals received via the ECE bit [RFC3168]. R/W: read-only ------------------------------------------------------------------------------ VariableName: SendStall Scope: standard ShortDescr: local resource stalls treated as congestion signals Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of interface stalls or other sender local resource limitations that are treated as congestion signals. R/W: read-only ------------------------------------------------------------------------------ VariableName: QuenchRcvd Scope: standard ShortDescr: ICMP Quench Messages received Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of ICMP quench messages that are treated as congestion signals. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 2Apath The following optional objects can be used to infer segment reordering on the path from the local sender to the remote receiver. ------------------------------------------------------------------------------ VariableName: RetranThresh Scope: standard ShortDescr: Duplicate ACKs needed to trigger FR Table: 2Apath . ProcType: Gauge32 Description: The number of duplicate acknowledgments required to trigger Fast Retransmit. Note that although this is constant in traditional Reno TCP implementations, it is adaptive in many newer TCPs. R/W: read-only ------------------------------------------------------------------------------ VariableName: NonRecovDAEpisodes RenameFrom: SndDupAckEpisodes Scope: standard ShortDescr: Dup Ack Episodes that did not trigger FR Table: 2Apath + ProcType: Integer32 Description: The number of duplicate acknowledgment episodes that did not trigger a Fast Retransmit because ACK advanced prior to the number of duplicate acknowledgments reaching RetranThresh. See [RFC2581]. In many implementations this is the number of times the "dupacks" counter is set to zero when it is non-zero but less than RetranThresh. Note that tcpEStatsPathNonRecovDAEpisodes divided by tcpEStatsPerfDataSegsOut is an estimate of the frequency of data reordering on the forward path. R/W: read-only ------------------------------------------------------------------------------ VariableName: SumOctetsReordered Scope: standard ShortDescr: Sum Octets Reordered Table: 2Apath + ProcType: Integer32 Description: The sum of the amounts SND.UNA advances on the acknowledgment which ends a dup-ack episode without a retransmission. Note tcpEStatsPathSumOctetsReordered divided by tcpEStatsPathNonRecovDAEpisodes is an estimates of the average reordering distance, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: NonRecovDA Scope: standard ShortDescr: Duplicate Acks attributed to Out-of-Order Table: 2Apath + ProcType: ZeroBasedCounter32 Description: Duplicate acks (or SACKS) that did not trigger a Fast Retransmit because ACK advanced prior to the number of duplicate acknowledgments reaching RetranThresh. In many implementations, this is the sum of the "dupacks" counter, just before it is set to zero because ACK advanced without a Fast Retransmit. Note that tcpEStatsPathNonRecovDA divided by tcpEStatsPathNonRecovDAEpisodes is an estimate of the average reordering distance in segments. R/W: read-only ------------------------------------------------------------------------------ VariableName: SpuriousFrDetected RenameFrom: AckAfterFR Scope: standard ShortDescr: ACKs following FR, but not due to FR (way ooo) Table: 3Astack + ProcType: ZeroBasedCounter32 Description: The number of acknowledgments reporting out-of-order segments after the Fast Retransmit algorithm has already retransmitted the segments. (For example as detected by the Eiffle algorithm, [RFC3522])." R/W: read-only ------------------------------------------------------------------------------ VariableName: SpuriousRtoDetected RenameFrom: AckAfterFR Scope: standard ShortDescr: ACKs following FR, but not due to FR (way ooo) Table: 3Astack + ProcType: ZeroBasedCounter32 Description: The number of acknowledgments reporting segments that have already be retransmitted due to a Retransmission Timeout. R/W: read-only ------------------------------------------------------------------------------ VariableName: DSACKDups Scope: standard ShortDescr: Duplicate Data DSACK Reports Table: 3Bstack + ProcType: ZeroBasedCounter32 Description: The number of duplicate segments reported to the local host by D-SACK blocks. See [RFC2883]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional objects instrument path MTU discovery. ------------------------------------------------------------------------------ VariableName: MaxMSS Scope: standard ShortDescr: Maximum MSS Table: 3Bstack + ProcType: Gauge32 Description: The maximum MSS, in octets. See [RFC1191]. R/W: read-only ------------------------------------------------------------------------------ VariableName: MinMSS Scope: standard ShortDescr: Minimum MSS Table: 3Bstack + ProcType: Gauge32 Description: The minimum MSS, in octets. See [RFC1191]. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 3Bstack The following optional objects instrument the senders buffer usage, including any buffering in the application interface to TCP and the retransmit queue. All "buffer memory" instruments are assumed to include OS data structure overhead. ------------------------------------------------------------------------------ VariableName: CurRetxQueue Scope: standard RenameFrom: CurRetranQueue ShortDescr: Current size of retransmit queue Table: 3Bstack . ProcType: Gauge32 Description: The current number of octets of data occupying the retransmit queue. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxRetxQueue Scope: standard RenameFrom: MaxRetranQueue ShortDescr: Maximum size of retransmit queue Table: 3Bstack + ProcType: Gauge32 Description: The maximum number of octets of data occupying the retransmit queue. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurAppWQueue Scope: standard ShortDescr: Current size of application write queue Table: 4Bapp . ProcType: Gauge32 Description: The current number of octets of application data buffered by TCP, pending first transmission, i.e. to the left of SND.NXT or SndMax. This data will generally be transmitted (and SND.NXT advanced to the left) as soon as there is available congestion window (cwnd) or receiver window (rwin). This is the amount of data readily available for transmission, without scheduling the application. TCP performance may suffer if there is insufficient queued write data. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxAppWQueue Scope: standard ShortDescr: Maximum size of application write queue Table: 4Bapp + ProcType: Gauge32 Description: The maximum number of octets of application data buffered by TCP, pending first transmission. This is the maximum value of tcpEStatsAppCurAppWQueue. This pair of objects can be used to determine if insufficient queued data is steady state (suggesting insufficient queue space) or transient (suggesting insufficient application performance or excessive CPU load or scheduler latency). R/W: read-only ------------------------------------------------------------------------------ VariableName: X_SBufMode Scope: internal ShortDescr: Send buffer mode ProcType: Gauge32 Description: A mechanism for changing the send buffering mode of a connection. Current values taken may be: (0) Default Linux kernel buffering (1) Web100 "autotuned" buffering R/W: read-write ------------------------------------------------------------------------------ VariableName: X_Sndbuf RenameFrom: Sndbuf SndbufGet Scope: internal ShortDescr: Socket sndbuf size ProcType: Gauge32 Description: The socket send buffer size is octets. Note that the meaning of this variable is implementation dependent. Particularly, it may or may not include the retransmit queue. R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 1Aperf The following objects instrument our receiver window updates to the remote sender. These can be used to determine if the local receiver is exerting flow control back pressure on the remote sender. ------------------------------------------------------------------------------ VariableName: CurRwinSent Scope: standard RenameFrom: CurrentRwinSent ShortDescr: current receiver window out Table: 1Aperf . ProcType: Gauge32 Description: The most recent window advertisement sent, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxRwinSent Scope: standard ShortDescr: maximum receiver window out Table: 1Aperf + ProcType: Gauge32 Description: The maximum window advertisement sent, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: ZeroRwinSent Scope: standard ShortDescr: Number of ACKS sent with zero receive windows Table: 1Aperf + ProcType: Gauge32 Description: The number of acknowledgments sent announcing a zero receive window, when the previously announced window was not zero. R/W: read-only ------------------------------------------------------------------------------ VariableName: LimRwin Scope: standard ShortDescr: Bound on announced receiver window Table: 5Btune + ProcType: Gauge32 Description: A control to set the maximum window advertisement which may be sent, in octets. R/W: read-write ------------------------------------------------------------------------------ SNMPcomment: 2Bpath The following optional objects are receiver side instruments of the path from the sender to the receiver. In general the receiver has less information about the state of the path, because the receiver does not have a robust mechanism to infer the sender's actions. ------------------------------------------------------------------------------ VariableName: DupAckEpisodes Scope: standard ShortDescr: Number of Duplicate Acks Sent when prior Ack was not duplicate Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of Duplicate Acks Sent when prior Ack was not duplicate. This is the number of times that a contiguous series of duplicate acknowledgments have been sent. This is an indication of the number of data segments lost or reordered on the path from the remote TCP endpoint to the near TCP endpoint. R/W: read-only ------------------------------------------------------------------------------ VariableName: DupAcksOut Scope: standard ShortDescr: Number of Duplicate Acks Sent Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: The number of duplicate ACKs sent. The ratio of tcpEStatsPathDupAcksOut to tcpEStatsPathDupAckEpisodes is an indication of reorder or recovery distance. R/W: read-only ------------------------------------------------------------------------------ VariableName: CERcvd Scope: standard ShortDescr: Received segments with Congestion Experienced bits Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: Received segments with Congestion Experienced bits. See [RFC3168]. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECNSent Scope: standard ShortDescr: Number of times CE bits have set ECN Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: Number of times CE bits have set ECN. See [RFC3168]. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECNNonceRcvd Scope: standard ShortDescr: Number of ECN Nonces received Table: 2Bpath + ProcType: ZeroBasedCounter32 Description: Number of ECN Nonces received. Note that the low bit is the same as the one bit nonce sum. R/W: read-only ------------------------------------------------------------------------------ VariableName: X_RcvRTT Scope: internal ShortDescr: Receiver RTT estimate Table: 3Bstack ProcType: Gauge32 Description: The receiver's RTT estimate, if available. Note that there is no standard for receiver RTT measurement. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurReasmQueue Scope: standard ShortDescr: Current size of reassembly queue Table: 3Bstack . ProcType: Gauge32 Description: The current number of octets of sequence space spanned by the reassembly queue. This is generally the difference between rcv.nxt and the sequence number of the right most edge of the reassembly queue. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxReasmQueue Scope: standard ShortDescr: Maximum size of reassembly queue Table: 3Bstack + ProcType: Gauge32 Description: The maximum value of tcpEStatsStackCurReasmQueue R/W: read-only ------------------------------------------------------------------------------ VariableName: CurAppRQueue Scope: standard ShortDescr: Current size of application read queue Table: 4Bapp . ProcType: Gauge32 Description: The current number of octets of application data that has been acknowledged by TCP but not yet delivered to the application. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxAppRQueue Scope: standard ShortDescr: Maximum size of application read queue Table: 4Bapp . ProcType: Gauge32 Description: The maximum number of octets of application data that has been acknowledged by TCP but not yet delivered to the application. R/W: read-only ------------------------------------------------------------------------------ VariableName: X_RBufMode Scope: internal ShortDescr: Send buffer mode ProcType: Gauge32 Description: A mechanism for changing the receive buffering mode of a connection. Current values taken may be: (0) Default Linux kernel buffering (1) Web100 "autotuned" buffering R/W: read-write ------------------------------------------------------------------------------ VariableName: X_Rcvbuf RenameFrom: Rcvbuf RcvbufGet Scope: internal ShortDescr: Socket rcvbuf size ProcType: Gauge32 Description: The socket receive buffer size is octets. Note that the meaning of this variable is implementation dependent. In particular, it may or may not include the reassembly queue. R/W: read-only ------------------------------------------------------------------------------ VariableName: X_wnd_clamp Scope: internal ShortDescr: X_wnd_clamp ProcType: Gauge32 Description: Code dissection. R/W: read-only ------------------------------------------------------------------------------ VariableName: X_rcv_ssthresh Scope: internal ShortDescr: X_rcv_ssthresh ProcType: Gauge32 Description: Code dissection. R/W: read-only ------------------------------------------------------------------------------ VariableName: X_dbg1 Scope: internal ShortDescr: X_dbg1 ProcType: Gauge32 Description: Debugging R/W: read-only ------------------------------------------------------------------------------ VariableName: X_dbg2 Scope: internal ShortDescr: X_dbg2 ProcType: Gauge32 Description: Debugging R/W: read-only ------------------------------------------------------------------------------ VariableName: X_dbg3 Scope: internal ShortDescr: X_dbg3 ProcType: Gauge32 Description: Debugging R/W: read-only ------------------------------------------------------------------------------ VariableName: X_dbg4 Scope: internal ShortDescr: X_dbg4 ProcType: Gauge32 Description: Debugging R/W: read-only ------------------------------------------------------------------------------ SNMPcomment: 1Aperf The following objects instrument receiver window updates from the far end-system to determine if the remote receiver has sufficient buffer space or is exerting flow-control back pressure on the local sender. ------------------------------------------------------------------------------ VariableName: CurRwinRcvd Scope: standard RenameFrom: CurrentRwinRcvd ShortDescr: Current Receiver Window Table: 1Aperf . ProcType: Gauge32 Description: The most recent window advertisement received, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: MaxRwinRcvd Scope: standard ShortDescr: Maximum Receiver Window Table: 1Aperf + ProcType: Gauge32 Description: The maximum window advertisement received, in octets. R/W: read-only ------------------------------------------------------------------------------ VariableName: ZeroRwinRcvd Scope: standard ShortDescr: Minimum Receiver Window Table: 1Aperf + ProcType: Gauge32 Description: The number of acknowledgments received announcing a zero receive window, when the previously announced window was not zero. R/W: read-only ------------------------------------------------------------------------------ CATEGORY: NULL CatDescr: NULL ------------------------------------------------------------------------------ LocalWords: perf