RFC 3287 (rfc3287) - Page 3 of 120
Remote Monitoring MIB Extensions for Differentiated Services
Alternative Format: Original Text Document
RFC 3287 DSMON MIB July 2002 o A set of fundamental applications described in RFC 2573 [RFC 2573] and the view-based access control mechanism described in RFC 2575 [RFC 2575]. A more detailed introduction to the current SNMP Management Framework can be found in RFC 2570 [RFC 2570]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the mechanisms defined in the SMI. This memo specifies a MIB module that is compliant to the SMIv2. A MIB conforming to the SMIv1 can be produced through the appropriate translations. The resulting translated MIB must be semantically equivalent, except where objects or events are omitted because no translation is possible (use of Counter64). Some machine readable information in SMIv2 will be converted into textual descriptions in SMIv1 during the translation process. However, this loss of machine readable information is not considered to change the semantics of the MIB. 2. Overview There is a need for a standardized way of monitoring the network traffic usage of Differentiated Services (DS) [RFC 2474] codepoint values. Each DS codepoint (DSCP) value may be given a different treatment by a forwarding device, and this affects which packets get dropped or delayed during periods of network congestion. The IETF DIFFSERV working group has redefined the semantics of the Type of Service (TOS) octet in the IP header, which is now called the 'DS field'. The 6-bit Codepoint (DSCP) portion is contained in the DS field, which provides for 64 different packet treatments for the implementation of differentiated network services. By polling DSCP usage counters, an NMS can determine the network throughput for traffic associated with different DSCPs. This data can then be analyzed in order to 'tune' DSCP 'allocations' within a network, based on the Quality of Service (QoS) policies for that network. Remote monitoring agents are typically implemented as independent software (and sometimes hardware) components, called 'RMON probes'. Note that DSMON-capable RMON probes simply collect and aggregate statistics, based on criteria (which includes the DSCP value) that can be determined by inspecting the contents of monitored packets and do not in any way monitor any aspect of a DS forwarding device's internal statistics. Bierman Standards Track
