3Com VCX V7122 SIP, User Manual

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3Com VCX V7122/SIP VoIP Gateway User Manual
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number is zero. In the case of Table objects, this instance number is the index into the
SNMP table. SNMP tables are special types of SNMP objects, which allow parallel
arrays of information to be supported. Tables are distinguished from scalar objects, in
that tables can grow without bounds. For example, SNMP defines the ifDescr object (as
a standard SNMP object) that indicates the text description of each interface supported
by a particular device. Since network devices can be configured with more than one
interface, this object could only be represented as an array.
By convention, SNMP objects are always grouped in an Entry directory, within an object with
a Table suffix. (The ifDescr object described above resides in the ifEntry directory contained
in the ifTable directory).
SNMP Extensibility Feature
One of the principal components of any respectable SNMP manager is a MIB Compiler that
allows new MIB objects to be added to the management system. When a MIB is compiled
into an SNMP manager, the manager is made aware of new objects that are supported by
agents on the network. The concept is similar to adding a new schema to a database.
Typically, when a MIB is compiled into the system, the manager creates new folders or
directories that correspond to the objects. These folders or directories can typically be
viewed with a MIB Browser, which is a traditional SNMP management tool incorporated into
virtually all network management systems.
The act of compiling the MIB allows the manager to know about the special objects
supported by the agent and access these objects as part of the standard object set.
VCX V7122/SIP Gateway Supported MIBs
The TrunkPack-VoIP Series contains an embedded SNMP Agent supporting the following
MIBs:
ƒ The Standard MIB (MIB-II) – The various SNMP values in the standard MIB are defined
in RFC 1213. The standard MIB includes various objects to measure and monitor IP
activity, TCP activity, UDP activity, IP routes, TCP connections, interfaces, and general
system description.
ƒ RTP MIB – The RTP MIB is supported per the RFC 2959. It contains objects relevant to
the RTP streams generated and terminated by the Gateway and to the RTCP information
related to these streams.
ƒ Trunk MIB – The Trunk MIB is supported per the RFC 2495. It contains objects relevant
to E1/T1 Trunk interfaces including performance monitoring, In this version, only the
dsx1ConfigTable fields and dsx1LineStatusChange NOTIFICATION (Trap) are
supported. Traps are received by an SNMP manager using a Network Interface.
ƒ ACBoardMIB – This 3Com proprietary MIB contains objects related both to the
configuration of the Gateway and channels as well as to run-time information. Through
this MIB, you can set up the Gateway configuration parameters, reset the Gateway, and
monitor the Gateway’s operational robustness and quality of service during run-time.