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 This document contains incomplete and unpublished research results.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 RFC 1902 "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)" ------------------------------------------------------------------------------ CATEGORY: CONNECTION ID CatDescr: The 5 tuple that uniquely identifies every connection. ------------------------------------------------------------------------------ VariableName: protocol ShortDescr: Protocol type for this connection Category: CONNECTION ID ProcType: Integer32 Description: Protocol type for this connection. R/W: read-only Reference: Comment: This could be used to support a common mib across multiple transport protocols. ------------------------------------------------------------------------------ VariableName: LocalAddress ShortDescr: Local IP Address Category: CONNECTION ID ProcType: Ip_Address Description: IP Address of the host from which the KIS was read. R/W: read-only Reference: RFC2012 (TCP-MIB v2) Comment: This is required for backward compatibility with RFC2012 ------------------------------------------------------------------------------ VariableName: LocalPort ShortDescr: Local Port Number Category: CONNECTION ID ProcType: Unsigned16 Description: The Local Host's TCP port number for a connection. R/W: read-only Reference: RFC2012 (TCP-MIB v2) Comment: This is required for backward compatibility with RFC2012 ------------------------------------------------------------------------------ VariableName: RemoteAddress ShortDescr: Remote IP Address Category: CONNECTION ID ProcType: Ip_Address Description: IP Address of the Remote host's end of a connection. R/W: read-only Reference: RFC2012 (TCP-MIB v2) Comment: This is required for backward compatibility with RFC2012 ------------------------------------------------------------------------------ VariableName: RemotePort ShortDescr: Remote Port Number Category: CONNECTION ID ProcType: Unsigned16 Description: The Remote Host's TCP port number for a connection. R/W: read-only Reference: RFC2012 (TCP-MIB v2) Comment: This is required for backward compatibility with RFC2012 ------------------------------------------------------------------------------ CATEGORY: CONNECTION STATE CatDescr: Flags indicating if various protocol features or algorithms are enabled. All of the options listed here are fully described in various standards documents. SNMPfile: 1conn SNMPprefix: tcpEStatsConnection ------------------------------------------------------------------------------ VariableName: State ShortDescr: TCP State Category: CONNECTION STATE ProcType: INTEGER Description: An integer value representing the connection state from the TCP State Transition Diagram. R/W: read-only Reference: RFC2012 (TCP-MIB v2) Transmission Control Protocol using SMIv2 Comment: This is patterned after the Connection Table in RFC2012 PossibleValues: wcStateClosed(1) wcStateListen(2) wcStateSynSent(3) wcStateSynReceived(4) wcStateEstablished(5) wcStateFinWait1(6) wcStateFinWait2(7) wcStateCloseWait(8) wcStateLastAck(9) wcStateClosing(10) wcStateTimeWait(11) wcStateDeleteTcb(12) ------------------------------------------------------------------------------ VariableName: SACKEnabled SNMPname: SACK ShortDescr: SACK Enabled Category: CONNECTION STATE ProcType: TruthValue Description: Non-zero if SACK has been negotiated ON by both ends of the connection. Zero otherwise. R/W: read-only Reference: RFC2018 TCP Selective Acknowledgment Options Comment: ------------------------------------------------------------------------------ VariableName: TimestampsEnabled SNMPname: TimeStamps ShortDescr: Timestamps Enabled Category: CONNECTION STATE ProcType: TruthValue Description: Non-zero if Timestamps have been negotiated ON by both ends of the connection in the SYN. Zero otherwise. R/W: read-only Reference: RFC1323 TCP Extensions for High Performance Comment: ------------------------------------------------------------------------------ VariableName: ECNEnabled SNMPname: ECN ShortDescr: Explicit Congestion Notification is Enabled Category: CONNECTION STATE ProcType: TruthValue Description: Non-zero if ECN has been negotiated ON. R/W: read-only Comment: Reference: ------------------------------------------------------------------------------ VariableName: NagleEnabled SNMPname: Nagle ShortDescr: Nagle Algorithm Enabled Category: CONNECTION STATE ProcType: TruthValue Description: Non-zero if the Nagle algorithm is being used by the Local Host on this connection. Zero otherwise. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: WinScaleRcvd RenameFrom: RecvWinScale ShortDescr: requested window scale Category: CONNECTION STATE ProcType: Integer32 PossibleValues: (-1..14) Description: The window scale value used by the Local Host in calculating incoming window sizes on this connection. Must be initialized to be < 0; Winshift will be considered to be in effect only if WinScaleSent and WinScaleRcvd are both >= 0. R/W: read-only Reference: RFC1323 TCP Extensions for High Performance Comment: ------------------------------------------------------------------------------ VariableName: WinScaleSent RenameFrom: SendWinScale ShortDescr: Requested Window Scale Out Category: CONNECTION STATE ProcType: Integer32 PossibleValues: (-1..14) Description: The window scale value used by the Local Host in calculating the advertised window on this connection. Must be initialized to be < 0; Winshift will be considered to be in effect only if WinScaleSent and WinScaleRcvd are both >= 0. R/W: read-only Reference: RFC1323 TCP Extensions for High Performance Comment: ------------------------------------------------------------------------------ CATEGORY: SYN OPTIONS CatDescr: Statistics on options present on the SYN and SYN-ACK. SNMPfile: 2synops SNMPprefix: tcpEStatsSynOpts ------------------------------------------------------------------------------ VariableName: MSSSent ShortDescr: Mss Option sent Category: SYN OPTIONS ProcType: Gauge32 Description: The value sent in an MSS option, or zero if none R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MSSRcvd ShortDescr: MSS Option received Category: SYN OPTIONS ProcType: Gauge32 Description: The value received in an MSS option, or zero if none R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SACKSent ShortDescr: SACKok was sent in SYN or SYN-ACK Category: SYN OPTIONS ProcType: TruthValue Description: True if SACKok was sent in SYN or SYN-ACK. R/W: read-only Reference: Comment: SACK is enabled only of both SACKSent and SACKRcvd are both > 0 ------------------------------------------------------------------------------ VariableName: SACKRcvd ShortDescr: SACKok was seen in SYN or SYN-ACK Category: SYN OPTIONS ProcType: TruthValue Description: True if SACKok was found in SYN or SYN-ACK. R/W: read-only Reference: Comment: SACK is enabled only of both SACKSent and SACKRcvd are both > 0 ------------------------------------------------------------------------------ VariableName: TimestampSent SNMPname: TimeStampSent ShortDescr: Timestamp sent in SYN or SYN-ACK Category: SYN OPTIONS ProcType: TruthValue Description: True if Timestamp was sent in SYN or SYN-ACK. R/W: read-only Reference: Comment: Timestamp is enabled only of both TimestampSent and TimestampRcvd are both > 0 ------------------------------------------------------------------------------ VariableName: TimestampRcvd SNMPname: TimeStampRcvd ShortDescr: Timestamp received in SYN or SYN-ACK Category: SYN OPTIONS ProcType: TruthValue Description: True if Timestamp was found in SYN or SYN-ACK. R/W: read-only Reference: Comment: Timestamp is enabled only of both TimestampSent and TimestampRcvd are both > 0 ------------------------------------------------------------------------------ VariableName: ActiveOpen ShortDescr: Local Host Did an Active Open Category: SYN OPTIONS ProcType: TruthValue Description: True if local host was the one that sent the SYN. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ CATEGORY: DATA TRAFFIC CatDescr: Statistics on aggregate packets and data sent on a connection. These provide a direct measure of the Internet capacity consumed by a connection. SNMPfile: 3data SNMPprefix: tcpEStatsData ------------------------------------------------------------------------------ VariableName: PktsOut ShortDescr: Total Packets Out Category: DATA TRAFFIC ProcType: Counter32 Description: The total number of packets that have been sent on this connection by the Local Host. R/W: read-only Reference: Comment: Includes retransmitted packets, SYN pkts, etc., but not FIN pkts without data, or RSTs. Will closely approximate DataPktsOut + AckPktsOut + PktsRetrans. ------------------------------------------------------------------------------ VariableName: DataPktsOut ShortDescr: Data Packets Out Category: DATA TRAFFIC ProcType: Counter32 Description: The number of data packets (with len > 0) that have been sent on this connection by the Local Host. R/W: read-only Reference: Comment: Does not include retransmitted packets. Does include pkts in which ACK advances, as long as the pkt contains data. ------------------------------------------------------------------------------ VariableName: AckPktsOut ShortDescr: Ack Packets Out Category: DATA TRAFFIC ProcType: Counter32 Description: The number of pure ack packets that have been sent on this connection by the Local Host. R/W: read-only Reference: Comment: assumes that pure acks have no data. Includes SYN-ACK. ------------------------------------------------------------------------------ VariableName: DataBytesOut ShortDescr: Data Bytes Out Category: DATA TRAFFIC ProcType: Counter64 Description: The number of bytes of data that have been sent on this connection by the Local Host, not including retransmitted packets. R/W: read-only Reference: Comment: Does not include SYN or FIN. ------------------------------------------------------------------------------ VariableName: PktsIn ShortDescr: Total Packets In Category: DATA TRAFFIC ProcType: Counter32 Description: The total number of packets that have been received on this connection by the Local Host. R/W: read-only Reference: Comment: PktsIn should be slightly greater or equal to DataPktsIn + AckPktsIn. Includes all packets that pass checksum and header length checks. ------------------------------------------------------------------------------ VariableName: DataPktsIn ShortDescr: Total Data Packets In Category: DATA TRAFFIC ProcType: Counter32 Description: The number of data packets (with len > 0) that have been received on this connection by the Local Host. R/W: read-only Reference: Comment: Includes pkts for which ACK advances too, as long as it contains data. Includes out-of-order pkts. ------------------------------------------------------------------------------ VariableName: AckPktsIn ShortDescr: Ack Packets In Category: DATA TRAFFIC ProcType: Counter32 Description: The number of valid pure ack packets that have been received on this connection by the Local Host. R/W: read-only Reference: Comment: Assumes that pure ACKs have no data. Includes duplicate ACKs. A valid ACK is snd_una <= ack <= snd_nxt ------------------------------------------------------------------------------ VariableName: DataBytesIn ShortDescr: Data Bytes In Category: DATA TRAFFIC ProcType: Counter64 Description: The number of bytes of non-duplicate data that have been received on this connection by the Local Host. R/W: read-only Reference: Comment: Includes data bytes of any type, but does not include SYN or FIN. It does not include bytes of duplicate data (resulting from retransmission of packets that were not lost). ------------------------------------------------------------------------------ CATEGORY: DATA SEQUENCE CatDescr: Sequence numbers used by the sending side of the connection ------------------------------------------------------------------------------ VariableName: snd_una SNMPname: SndUna ShortDescr: Oldest Unacknowledged Sequence Number Category: DATA SEQUENCE ProcType: Counter32 Description: Oldest Unacknowledged Sequence Number. R/W: read-only Reference: RFC-793: TCP PROTOCOL SPECIFICATION Comment: ------------------------------------------------------------------------------ VariableName: snd_nxt SNMPname: SndNxt ShortDescr: Next Sequence Number to be Sent Category: DATA SEQUENCE ProcType: Integer32 Description: Next Sequence Number to be Sent. Note that many TCP implementations retransmit lost data by pulling SndNxt back to the lost data. R/W: read-only Reference: RFC-793: TCP PROTOCOL SPECIFICATION Comment: ------------------------------------------------------------------------------ VariableName: snd_max SNMPname: SndMax ShortDescr: Maximum Value of snd_nxt Category: DATA SEQUENCE ProcType: Counter32 Description: This is equal to snd_next except when doing Tahoe style recovery. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: ThruBytesSent ShortDescr: Total throughput bytes sent Category: DATA SEQUENCE ProcType: Counter64 Description: Total throughput bytes delivered and acknowledged by the remote receiver as indicated by the 64 bit sum of changes in snd_una. R/W: read-only Comment: ------------------------------------------------------------------------------ VariableName: SndISS SNMPname: SndInitial ShortDescr: Initial SYN sequence number Category: DATA SEQUENCE ProcType: Counter32 Description: Initial SYN sequence number. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SendWraps ShortDescr: Number of sequence space wraps Category: DATA SEQUENCE ProcType: Counter32 Description: This is the number of times snd_max "passes" ISS. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: rcv_nxt SNMPname: RcvNxt ShortDescr: Next sequence number expected on an incoming segment Category: DATA SEQUENCE ProcType: Counter32 Description: Next sequence number expected on an incoming segment, and is the left or lower edge of the receive window. R/W: read-only Reference: RFC-793: TCP PROTOCOL SPECIFICATION ------------------------------------------------------------------------------ VariableName: ThruBytesReceived ShortDescr: Total throughput bytes received Category: DATA SEQUENCE ProcType: Counter64 Description: Total throughput bytes received and acknowledged to the remote sender as indicated by the 64 bit sum of changes in rcv_nxt. R/W: read-only Comment: ------------------------------------------------------------------------------ VariableName: RecvISS SNMPname: RecInitial ShortDescr: Initial SYN sequence number Category: DATA SEQUENCE ProcType: Counter32 Description: Initial SYN sequence number. R/W: read-only ------------------------------------------------------------------------------ VariableName: RecvWraps SNMPname: RecWraps ShortDescr: Number of sequence space wraps Category: DATA SEQUENCE ProcType: Counter32 Description: This is the number of times rcv_max "passes" ISS. R/W: read-only ------------------------------------------------------------------------------ VariableName: CurrTime SNMPname: CurTime ShortDescr: Current Time Category: DATA TRAFFIC ProcType: Counter32 SNMPType: DateAndTime Description: Current Time. R/W: read-only Comment: The proc version is the low 32 bits of (seconds_since_1970) * 1000000 + (usec_clock) ------------------------------------------------------------------------------ VariableName: StartTime ShortDescr: Start Time Category: DATA TRAFFIC ProcType: Counter32 SNMPType: DateAndTime Description: Time of the start of the connection. R/W: read-only Comment: The proc version is the low 32 bits of (seconds_since_1970) * 1000000 + (usec_clock) ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ CATEGORY: SENDER CONGESTION TRIAGE CatDescr: First level instruments to determine which subsystems are controlling overall performance by throttling TCP data transmission. The three parallel sets of instruments measure the extent to which the receiver window, network congestion or the senders available data limit TCP's performance. They reflect bottlenecks at the receiver, network or sender respectively. SNMPfile: 4congest SNMPprefix: tcpEStatsSndCong ------------------------------------------------------------------------------ VariableName: SndLimTransSender SNMPname: SndLimTransSnd ShortDescr: Sender Limited Transitions Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The number of transitions into the "Sender Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops because there no more data in sender's buffer. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SndLimTimeSender SNMPname: SndLimTimeSnd ShortDescr: Sender Limited Time Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The cumulative time (in msecs) spent in the "Sender Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops because there is no more data in sender's buffer. R/W: read-only Reference: Comment: Need to implement timer updates for when the connection is idle ------------------------------------------------------------------------------ VariableName: SndLimBytesSender SNMPname: SndLimBytesSnd ShortDescr: Sender Limited Bytes Category: SENDER CONGESTION TRIAGE ProcType: Counter64 Description: The cumulative bytes sent while in the "Sender Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops because there is no more data in sender's buffer. R/W: read-only Reference: Comment: There is a serious fence post/ boundary question that needs to be investigated. ------------------------------------------------------------------------------ VariableName: SndLimTransCwnd ShortDescr: Congestion Limited Transitions Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The number of transitions into the "Congestion Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SndLimTimeCwnd ShortDescr: Congestion Limited Time Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The cumulative time (in msecs) spent in the "Congestion Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to congestion. R/W: read-only Reference: Comment: Need to implement timer updates for when the connection is idle ------------------------------------------------------------------------------ VariableName: SndLimBytesCwnd ShortDescr: Congestion Limited Bytes Category: SENDER CONGESTION TRIAGE ProcType: Counter64 Description: The cumulative bytes sent while in the "Congestion Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to congestion. R/W: read-only Reference: Comment: There is a serious fence post/ boundary question that needs to be investigated. ------------------------------------------------------------------------------ VariableName: SndLimTransRwin ShortDescr: Receiver Limited Transitions Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The number of transitions into the "Receiver Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to Receiver not being able to receive data. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SndLimTimeRwin ShortDescr: Receiver Limited Time Category: SENDER CONGESTION TRIAGE ProcType: Counter32 Description: The cumulative time (in msecs) spent in the "Receiver Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to Receiver not being able to receive data. R/W: read-only Reference: Comment: Need to implement timer updates for when the connection is idle ------------------------------------------------------------------------------ VariableName: SndLimBytesRwin ShortDescr: Receiver Limited Bytes Category: SENDER CONGESTION TRIAGE ProcType: Counter64 Description: The cumulative bytes sent while in the "Receiver Limited" state, as determined by the Local Host, when the Local Host is a sender. This state is entered whenever TCP transmission stops due to Receiver not being able to receive data. R/W: read-only Reference: Comment: There is a serious fence post/ boundary question that needs to be investigated. ------------------------------------------------------------------------------ CATEGORY: SENDER CONGESTION MODEL CatDescr: Instruments on all events needed to model congestion along the network path. The instruments are sufficient to fit the actual performance to an updated macroscopic performance model. This in turn reveals the nature of the congestion. ------------------------------------------------------------------------------ VariableName: SlowStart ShortDescr: Slow Start Window Opens Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: Slow Start Window Opens. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CongAvoid ShortDescr: Congestion Avoidance Window Opens Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: Congestion Avoidance Window Opens. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CongestionSignals SNMPname: CongSignals RenameFrom: Recoveries ShortDescr: Total Congestion Signals. Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: The number of multiplicative downward congestion window adjustments due to all forms of congestion signals, including Fast Retransmit, ECN and timeouts. Congestion events which are backed out or suppressed due to overlap with other events (e.g. Fast Retransmit or ECN followed by a timeout) SHOULD NOT be included. Note that retransmission timeouts reduce the window implicitly by updating ssthresh and a subsequent slowstart. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: OtherReductions ShortDescr: Other Congestion Window Reductions Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: The number of congestion window reductions made by the Local Host as the result of anything other than AIMD congestion algorithms. All window reductions MUST be counted as either CongestionSignals or OtherReductions. Examples of non-multiplicative window reductions include slowstart restart and experimental algorithms such as Vegas [VEGAS] CAM. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CongestionOverCount SNMPname: CongOverCount ShortDescr: Overcounted congestion Signals Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: The number of events counted in CongestionSignals, which were backed out after it is infeasible to backout related variables such as SumCwndAtCong. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CurrentCwnd SNMPname: CurCwnd ShortDescr: Current Congestion Window Category: SENDER CONGESTION MODEL ProcType: Gauge32 Description: The Local Host's current value of snd_cwnd on this connection, in bytes. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SumCwndAtCong RenameFrom: SumCwndAtRecv ShortDescr: Sum Congestion Window at Congestion Category: SENDER CONGESTION MODEL ProcType: Counter32 Description: The sum of the Local Host's values of snd_cwnd captured each time recovery is entered, in bytes. This MUST be updated with CongestionSignals such that the ratio is the average window at congestion signal. R/W: read-only Reference: Comment: avg cwnd at loss is SumCwndAtRecov / Recoveries; may be deprecated in the future ------------------------------------------------------------------------------ VariableName: MaxCwnd ShortDescr: Maximum Congestion Window Category: SENDER CONGESTION MODEL ProcType: Gauge32 Description: The largest value attained by the Local Host's snd_cwnd on this connection, in bytes. R/W: read-only Reference: Comment: Should exclude slowstart ------------------------------------------------------------------------------ VariableName: CurrentSsthresh SNMPname: CurSsthresh ShortDescr: Current Slowstart Threshold Category: SENDER CONGESTION MODEL ProcType: Gauge32 Description: The Local Host's current value of snd_ssthresh on this connection, in bytes. R/W: read-only Reference: Comment: could be read directly from the TCPCB upon request by proc or SNMP to avoid numerous copies into the stats structure. ------------------------------------------------------------------------------ VariableName: MaxSsthresh ShortDescr: Maximum Slowstart Threshold Category: SENDER CONGESTION MODEL ProcType: Gauge32 Description: The largest non-initial value attained by the Local Host's snd_ssthresh on this connection, in bytes. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MinSsthresh ShortDescr: Minimum Slowstart Threshold Category: SENDER CONGESTION MODEL ProcType: Gauge32 Description: The smallest value attained by the Local Host's snd_ssthresh on this connection, in bytes. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER PATH LOSS MODEL CatDescr: Instruments that characterize the segment loss mechanism by collecting statistics on how the losses are correlated to other losses and protocol events. SNMPfile: 5path SNMPprefix: tcpEStatsPath ------------------------------------------------------------------------------ VariableName: FastRetran ShortDescr: Fast Retransmits Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of invocations of the Fast Retransmit algorithm when Local Host is the sender. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: Timeouts ShortDescr: Number of Initial Timeouts Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The total number of timeouts experienced by the connection, when the Local Host is the sender and the RTO multiplier is 1. R/W: read-only Reference: RFC2988 Comment: ------------------------------------------------------------------------------ VariableName: SubsequentTimeouts ShortDescr: Subsequent (repeated) Timeouts Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The total number of timeouts experienced by the connection, when the Local Host is the sender and the RTO multiplier is greater than one. R/W: read-only Reference: RFC2988 Comment: ------------------------------------------------------------------------------ VariableName: CurrTimeoutCount SNMPname: CurTimeoutCount ShortDescr: Current Repeated Timeout Count Category: SENDER PATH LOSS MODEL ProcType: Gauge32 Description: Current number of times that RTO has been increased due to repeated timeouts. The timeout multiplier is typically 2^CurrTimeoutCount. R/W: read-only Reference: Comment: Reword ------------------------------------------------------------------------------ VariableName: AbruptTimeouts RenameFrom: TimeoutsAfterFR ShortDescr: Abrupt Timeouts Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: Total number of timeouts that occurred without any preceding duplicate acknowledgments or other hints of congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: PktsRetrans ShortDescr: Packets With Retransmitted Data Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of pkts retransmitted on the connection by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: BytesRetrans ShortDescr: Retransmitted Bytes Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of bytes retransmitted on the connection by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: DupAcksIn ShortDescr: Number of Duplicate Acks Received Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of duplicate ACKs received on the connection by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SACKsRcvd ShortDescr: Number of SACKs Options Received Change: Redefine to be SACK Options. Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of SACK options on the connection, received by the Local Host, that represent new data arriving at the Remote Host. R/W: read-only Reference: RFC2018 TCP Selective Acknowledgment Options Comment: Count of SACK options ------------------------------------------------------------------------------ VariableName: SACKBlocksRcvd ShortDescr: Number of SACKs blocks Received Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: The number of SACK blocks on the connection, received by the Local Host, that represent new data arriving at the Remote Host. R/W: read-only Reference: RFC2018 TCP Selective Acknowledgment Options Comment: Count of SACK blocks and not SACK options ------------------------------------------------------------------------------ VariableName: PreCongSumRTT ShortDescr: Sum of the RTT as measured just before congestion Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: Sum of the RTT as measured just before congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: PreCongCountRTT ShortDescr: Count of the RTT as measured just before congestion Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: Count of the RTT as measured just before congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: PostCongSumRTT ShortDescr: Sum of the RTT as measured just after congestion Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: Sum of the RTT as measured just after congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: PostCongCountRTT ShortDescr: Count of the RTT as measured just after congestion Category: SENDER PATH LOSS MODEL ProcType: Counter32 Description: Count of the RTT as measured just after congestion. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER PATH OTHER SIGNALS CatDescr: Instruments at the sender to detect other types of non-loss congestion signals such as source quench or ECN. ------------------------------------------------------------------------------ VariableName: ECNsignals ShortDescr: All ECN congestions signals Category: SENDER PATH OTHER SIGNALS ProcType: Counter32 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 Comment: ------------------------------------------------------------------------------ VariableName: ECERcvd ShortDescr: ECE congestions signals Category: SENDER PATH OTHER SIGNALS ProcType: Counter32 Description: The number of Congestion Signals received via the RFC3168 ECE bit. R/W: read-only Comment: ------------------------------------------------------------------------------ VariableName: SendStall ShortDescr: local resource stalls treated as congestion signals Category: SENDER PATH OTHER SIGNALS ProcType: Counter32 Description: The number of interface stalls or other sender local resource limitations that are treated as congestion signals. R/W: read-only Comment: ------------------------------------------------------------------------------ VariableName: QuenchRcvd ShortDescr: ICMP Quench Messages received Category: SENDER PATH OTHER SIGNALS ProcType: Counter32 Description: The number of ICMP quench messages that are treated a congestion signals. R/W: read-only Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER PATH REORDER MODEL CatDescr: Instruments at the sender to infer that the TCP's reliable delivery mechanisms are being confused by packet reordering on the path from the sender to the receiver. ------------------------------------------------------------------------------ VariableName: RetranThresh ShortDescr: Duplicate ACKs needed to trigger FR Category: SENDER PATH REORDER MODEL ProcType: Gauge32 Description: Duplicate ACKs needed to trigger FR. R/W: read-only Reference: Comment: Constant in most current TCPs. Subject to current research. ------------------------------------------------------------------------------ VariableName: NonRecovDA ShortDescr: Duplicate Acks attributed to Out-of-Order Category: SENDER PATH REORDER MODEL ProcType: Counter32 Description: Duplicate acks (or SACKS) that did not trigger fastretransmit because they were withdrawn prior to reaching RetranThresh. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: AckAfterFR ShortDescr: ACKs following FR, but not due to FR (way ooo) Category: SENDER PATH REORDER MODEL ProcType: Counter32 Description: ACKs following FR, but not due to FR (way out-of-order). @@@@@ This is intended to instrument premature fast retransmits. It may be as simple as counting partial acks that are not followed by more duplicate acknowledgements. This may also instrument the Eifel algorithm. R/W: read-only Reference: Comment: May be hard to implement/poorly specified - this should be a future Eiffle instrument. ------------------------------------------------------------------------------ VariableName: DSACKDups ShortDescr: Duplicate Data DSACK Reports Category: SENDER PATH REORDER MODEL ProcType: Counter32 Description: The number of duplicate segments by the Remote Host using DSACKs. R/W: read-only Reference: Floyd and others. "An Extension to the Selective Acknowledgment (SACK) Option for TCP," Internet Draft August 1999, draft-floyd-sack-00.txt. Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER PATH RTT CatDescr: Instruments on the round trip time and the retransmission timeout timer. ------------------------------------------------------------------------------ VariableName: SampledRTT SNMPname: SampleRTT ShortDescr: Most recent RTT sample Category: SENDER PATH RTT ProcType: Gauge32 Description: The most recent round trip time sample in milliseconds for this connection, as seen by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SmoothedRTT ShortDescr: Smoothed RTT Category: SENDER PATH RTT ProcType: Gauge32 Description: The smoothed round trip time in milliseconds for this connection, as seen by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MaxRTT ShortDescr: Maximum RTT Category: SENDER PATH RTT ProcType: Gauge32 Description: The maximum round trip time sample seen on this connection by the Local Host, in milliseconds. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MinRTT ShortDescr: Minimum RTT Category: SENDER PATH RTT ProcType: Gauge32 Description: The smallest round trip time sample seen on this connection by the Local Host, in milliseconds. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: SumRTT ShortDescr: Cumulative RTT Category: SENDER PATH RTT ProcType: Counter64 Description: Cumulative round trip times seen on this connection by the Local Host, in milliseconds. R/W: read-only Reference: Comment: To be used with CountRTT to find the Average RTT in an interval ------------------------------------------------------------------------------ VariableName: CountRTT ShortDescr: Count of RTT Samples included in SumRTT Category: SENDER PATH RTT ProcType: Counter32 Description: Count of RTT samples included in SumRTT. R/W: read-only Reference: Comment: To be used with SumRTT to find the Average RTT in the interval ------------------------------------------------------------------------------ VariableName: CurrentRTO SNMPname: CurRTO ShortDescr: Current Retransmission Timer Category: SENDER PATH RTT ProcType: Gauge32 Description: The current value of the retransmit timeout limit (in milliseconds, not including the backoff timer) for this connection, as kept by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MaxRTO ShortDescr: Maximum Retransmission Timer Category: SENDER PATH RTT ProcType: Gauge32 Description: The maximum value of the retransmit timeout limit (in milliseconds, not including the backoff timer) for this connection, as seen by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MinRTO ShortDescr: Minimum Retransmission Timer Category: SENDER PATH RTT ProcType: Gauge32 Description: The smallest value of the retransmit timeout limit (in milliseconds, not including the backoff timer) for this connection, as seen by the Local Host. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER PATH SEGMENT SIZE CatDescr: Sender's maximum segment size, and the range of values explored by the MTU discovery algorithm. ------------------------------------------------------------------------------ VariableName: CurrentMSS SNMPname: CurMSS ShortDescr: Current Maximum Segment Size Category: SENDER PATH SEGMENT SIZE ProcType: Gauge32 Description: The current "maximum segment size" in bytes used by the Local Host for this connection. R/W: read-only Reference: RFC1191 Path MTU Discovery Comment: ------------------------------------------------------------------------------ VariableName: MaxMSS ShortDescr: Maximum MSS Category: SENDER PATH SEGMENT SIZE ProcType: Gauge32 Description: The maximum value of the "maximum segment size" in bytes used by the Local Host for this connection. R/W: read-only Reference: RFC1191 Path MTU Discovery Comment: ------------------------------------------------------------------------------ VariableName: MinMSS ShortDescr: Minimum MSS Category: SENDER PATH SEGMENT SIZE ProcType: Gauge32 Description: The smallest value of the "maximum segment size" in bytes used by the Local Host for this connection. R/W: read-only Reference: RFC1191 Path MTU Discovery Comment: ------------------------------------------------------------------------------ CATEGORY: SENDER BUFFER CatDescr: Instruments on the senders buffer usage, including any buffering in the application interface to TCP and the retransmit queue. SNMPfile: 6sendbuf SNMPprefix: tcpEStatsSendBuff ------------------------------------------------------------------------------ VariableName: Sndbuf SNMPname: SndBuf RenameFrom: SndbufGet ShortDescr: Available sender buffer memory Category: SENDER BUFFER ProcType: Gauge32 Description: The current total amount of sender buffer memory available to the connection. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CurRetranQueue ShortDescr: Current size of retransmit queue Category: SENDER BUFFER ProcType: Gauge32 Description: The current amount of memory used for the retransmit queue. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: MaxRetranQueue ShortDescr: Maximum size of retransmit queue Category: SENDER BUFFER ProcType: Gauge32 Description: The maximum amount of memory used for the retransmit queue. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: CurAppWQueue ShortDescr: Current size of application write queue Category: SENDER BUFFER ProcType: Gauge32 Description: The current amount of memory used to hold data that has been written by the application, but has yet to be transmitted on the network for the first time. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: MaxAppWQueue ShortDescr: Maximum size of application write queue Category: SENDER BUFFER ProcType: Gauge32 Description: The maximum amount of memory used to hold data that has been written by the application, but has yet to be transmitted on the network for the first time. R/W: read-only Reference: ------------------------------------------------------------------------------ CATEGORY: SENDER BUFFER TUNING CatDescr: Sender side tuning controls, including autotuning limits and "manual" controls ------------------------------------------------------------------------------ VariableName: STuneMode RenameFrom: SAutoMode ShortDescr: Sender tuning mode Category: SENDER BUFFER TUNING ProcType: INTEGER Description: The mode used for the sender-side TCP tuning by the Local Host. R/W: read-write Reference: http://www.psc.edu/networking/auto.html Comment: PossibleValues: sndTModeDEFAULT(0) /* use app/system default */ sndTModeSETSOCKOPT(1) /* application set sndbuf size */ sndTModeFIXED(2) /* constant buffer size */ sndTModeAUTO(3) /* auto tune */ sndTModeEXP1(4) /* future */ sndTModeEXP2(5) /* future */ ------------------------------------------------------------------------------ VariableName: SndbufSet ShortDescr: Set the available sender buffer memory Category: SENDER BUFFER TUNING ProcType: Gauge32 Description: A read/write gage to manually set the current buffer size, when STuneMode is sndTModeFIXED. Reading SndbufSet always reports the most recent write to SndbufSet, even if STuneMode is not sndTModeFIXED. Note that when entering manual (aka fixed) tuning modes SndbufSet should be updated before STuneMode. R/W: read-only Reference: Comment: This variable only has meaning in sndTModeFIXED ------------------------------------------------------------------------------ VariableName: SAppBuf RenameFrom: SndbufMin ShortDescr: Set the autotuning minimum buffer Category: SENDER BUFFER TUNING ProcType: Gauge32 Description: Advise to the auto-tuning algorithm in regards to the amount of buffer used to decouple the application from the TCP end-point. e.g. for the sender, limits (high, low or soft reservation) on the data queued before it is first transmitted. R/W: read-write Reference: Comment: ------------------------------------------------------------------------------ VariableName: SMaxWinBuf RenameFrom: SndbufMax ShortDescr: Maximum autotuning window buffer Category: SENDER BUFFER TUNING ProcType: Gauge32 Description: Advise to the auto-tuning algorithm in regards to the amount of buffer be used to support TCP retransmissions. e.g. limits on the TCP retransmit buffer. Its precise definition is tuning mode specific. R/W: read-write Reference: Comment: ------------------------------------------------------------------------------ VariableName: SXtra ShortDescr: Autotuning extra arg Category: SENDER BUFFER TUNING ProcType: Gauge32 Description: Additional mode specific advise to the auto-tuning algorithm. R/W: read-only Comment: Reference: ------------------------------------------------------------------------------ VariableName: STuneErr RenameFrom: SAutoErr ShortDescr: Sender tuning mode error flag Category: SENDER BUFFER TUNING ProcType: TruthValue Description: True indicates an tuning error. Error indications must be explicitly cleared. R/W: read-write Reference: Comment: A possible autotuning error would be when the application sets sndbuf with setsockopt. ------------------------------------------------------------------------------ CATEGORY: LOCAL RECEIVER CatDescr: Instruments on the state of the Local receiver. SNMPfile: 7receiver SNMPprefix: tcpEStatsRec ------------------------------------------------------------------------------ VariableName: CurrentRwinSent SNMPname: CurRwinSent ShortDescr: current receiver window out Category: LOCAL RECEIVER ProcType: Gauge32 Description: The current receiver window, in bytes, advertised by the Local Host for this connection. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: MaxRwinSent ShortDescr: maximum receiver window out Category: LOCAL RECEIVER ProcType: Gauge32 Description: The maximum receiver window, in bytes, ever advertised by the Local Host for this connection. R/W: read-only Reference: Comment: The value used for this parameter is after the window scale has been applied, ie. after the window has been shifted. ------------------------------------------------------------------------------ VariableName: MinRwinSent ShortDescr: minimum receiver window out Category: LOCAL RECEIVER ProcType: Gauge32 Description: The minimum receiver window, in bytes, ever advertised by the Local Host for this connection. R/W: read-only Reference: Comment: The value used for this parameter is after the window scale has been applied, ie. after the window has been shifted. ------------------------------------------------------------------------------ VariableName: OutOfWindowDiscards ShortDescr: Packets discarded because they fail a window test Category: LOCAL RECEIVER ProcType: Counter32 Description: Packets discarded because they fail a window test, including data, ack number or PAWS. R/W: read-only Comment: ------------------------------------------------------------------------------ VariableName: OutOfWindowReason ShortDescr: Identifies the window test that most recently failed Category: LOCAL RECEIVER ProcType: INTEGER Description: Identifies the window test that most recently failed R/W: read-only Comment: Reference: PossibleValues: belowDataWindow(1) /* network reordering, window probe or keep alive */ aboveDataWindow(2) /* impl bug or fraud only */ belowAckWindow(3) /* network reordering */ aboveAckWindow(4) /* impl bug or fraud only */ belowTSWindow(5) /* PAWS detected network reordering */ aboveTSWindow(6) /* impl bug or fraud only */ ------------------------------------------------------------------------------ VariableName: DupAckEpisodes ShortDescr: Number of Duplicate Acks Sent when prior Ack was not duplicate Category: LOCAL RECEIVER ProcType: Counter32 Description: The number of transitions into recovery states (requiring the transmission of duplicate acknowledgements) R/W: read-only ------------------------------------------------------------------------------ VariableName: DupAcksOut ShortDescr: Number of Duplicate Acks Sent Category: LOCAL RECEIVER ProcType: Counter32 Description: The number of duplicate ACKs sent on the connection by the Local Host. R/W: read-only ------------------------------------------------------------------------------ VariableName: CERcvd ShortDescr: Received segments with Congestion Experienced bits Category: LOCAL RECEIVER ProcType: Counter32 Description: Received segments with Congestion Experienced bits. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECNSent ShortDescr: Number of times CE bits have set ECN Category: LOCAL RECEIVER ProcType: Counter32 Description: Number of times CE bits have set ECN. R/W: read-only ------------------------------------------------------------------------------ VariableName: ECNNonceRcvd ShortDescr: Number of ECN Nonces received Category: LOCAL RECEIVER ProcType: Counter32 Description: Number of ECN Nonces received. Note that the low bit is the same as the 1 bit nonce sum. @@@@ not yet standards track R/W: read-only ------------------------------------------------------------------------------ CATEGORY: LOCAL RECEIVER BUFFER CatDescr: Instruments on the receiver buffer usage, including any buffering in the application interface to TCP and the reassembly queue. ------------------------------------------------------------------------------ VariableName: Rcvbuf SNMPname: RcvBuf RenameFrom: RcvbufGet ShortDescr: Available receiver buffer memory Category: LOCAL RECEIVER BUFFER ProcType: Gauge32 Description: The current total amount of receiver buffer memory available to the connection. R/W: read-only Reference: Comment: ------------------------------------------------------------------------------ VariableName: CurReasmQueue ShortDescr: Current size of reassembly queue Category: LOCAL RECEIVER BUFFER ProcType: Gauge32 Description: The current amount of memory used for the reassembly queue. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: MaxReasmQueue ShortDescr: Maximum size of reassembly queue Category: LOCAL RECEIVER BUFFER ProcType: Gauge32 Description: The maximum amount of memory used for the reassembly queue. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: CurAppRQueue ShortDescr: Current size of application read queue Category: LOCAL RECEIVER BUFFER ProcType: Gauge32 Description: The current amount of memory used to hold data that has been acknowledged to the sender but not delivered to the application. R/W: read-only Reference: ------------------------------------------------------------------------------ VariableName: MaxAppRQueue ShortDescr: Maximum size of application read queue Category: LOCAL RECEIVER BUFFER ProcType: Gauge32 Description: The maximum amount of memory used to hold data that has been acknowledged to the sender but not delivered to the application. R/W: read-only Reference: ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ CATEGORY: LOCAL RECEIVER BUFFER TUNING CatDescr: Receiver tuning controls, including autotuning limits and "manual" controls ------------------------------------------------------------------------------ VariableName: RTuneMode RenameFrom: RAutoMode ShortDescr: Receiver tuning mode Category: LOCAL RECEIVER BUFFER TUNING ProcType: INTEGER Description: The mode used for the receiver-side TCP tuning by the Local Host. R/W: read-write Reference: http://www.psc.edu/networking/auto.html Comment: PossibleValues: recTModeDEFAULT(0) /* use app/system default */ recTModeSETSOCKOPT(1) /* application set rcvbuf size */ recTModeFIXED(2) /* constant buffer size */ recTModeAUTO(3) /* auto tune */ recTModeEXP1(4) /* future */ recTModeEXP2(5) /* future */ ------------------------------------------------------------------------------ VariableName: RcvbufSet ShortDescr: Set the available receiver buffer memory Category: LOCAL RECEIVER BUFFER TUNING ProcType: Gauge32 Description: A read/write gauge to manually set the current buffer size, when RTuneMode is recTModeFIXED. Reading RcvbufSet always reports the most recent write to RcvbufSet, even if RTuneMode is not recTModeFIXED. Note that when entering manual (aka fixed) tuning modes RcvbufSet should be updated before RtuneMode. R/W: read-only Reference: Comment: This variable only has meaning in recTModeFIXED ------------------------------------------------------------------------------ VariableName: RAppBuf RenameFrom: RcvbufMin ShortDescr: Set the autotuning minimum buffer Category: LOCAL RECEIVER BUFFER TUNING ProcType: Gauge32 Description: Advise to the auto-tuning algorithm in regards to the amount of buffer used to decouple the application from the TCP end-point. e.g. for the receiver, limits on the amount of buffer space available for data that has been acknowledged but not read by the application. R/W: read-write Reference: Comment: ------------------------------------------------------------------------------ VariableName: RMaxWinBuf RenameFrom: RcvbufMax ShortDescr: Maximum autotuning window buffer Category: LOCAL RECEIVER BUFFER TUNING ProcType: Gauge32 Description: Advise to the auto-tuning algorithm in regards to the amount of buffer be used to support TCP retransmissions. e.g. limits on the TCP reassembly buffer. Its precise definition is tuning mode specific. R/W: read-write Reference: Comment: ------------------------------------------------------------------------------ VariableName: RXtra ShortDescr: Autotuning extra arg Category: LOCAL RECEIVER BUFFER TUNING ProcType: Gauge32 Description: Additional mode specific advise to the auto-tuning algorithm. R/W: read-only Comment: Reference: ------------------------------------------------------------------------------ VariableName: RTuneErr RenameFrom: RAutoErr ShortDescr: Receiver tuning mode error flag Category: LOCAL RECEIVER BUFFER TUNING ProcType: TruthValue Description: True indicates an tuning error. Error indications must be explicitly cleared. R/W: read-write Reference: Comment: A possible autotuning error would be when the application sets rcvbuf with setsockopt. ------------------------------------------------------------------------------ CATEGORY: OBSERVED RECEIVER WINDOW CatDescr: Instruments on receiver window updates used to infer the receiver's state. These can be collected at the sender or anywhere along the network path, including at the receiver. SNMPfile: 8rwin SNMPprefix: tcpEStatsObsRec ------------------------------------------------------------------------------ VariableName: CurrentRwinRcvd SNMPname: CurRwinRcvd ShortDescr: Current Receiver Window Category: OBSERVED RECEIVER WINDOW ProcType: Gauge32 Description: The current receiver window, in bytes, advertised by the Remote Host for this connection. R/W: read-only Reference: Comment: The value used for this parameter is after the window scale has been applied, ie. after the window has been shifted. ------------------------------------------------------------------------------ VariableName: MaxRwinRcvd ShortDescr: Maximum Receiver Window Category: OBSERVED RECEIVER WINDOW ProcType: Gauge32 Description: The maximum receiver window, in bytes, ever advertised by the Remote Host for this connection. R/W: read-only Reference: Comment: The value used for this parameter is after the window scale has been applied, ie. after the window has been shifted. ------------------------------------------------------------------------------ VariableName: MinRwinRcvd ShortDescr: Minimum Receiver Window Category: OBSERVED RECEIVER WINDOW ProcType: Gauge32 Description: The minimum receiver window, in bytes, ever advertised by the Remote Host for this connection. R/W: read-only Reference: Comment: The value used for this parameter is after the window scale has been applied, ie. after the window has been shifted. ------------------------------------------------------------------------------