User`s manual

MP-1xx/H.323 User’s Manual 7. Device Management
Version 4.2 Beta 81 June 2003
7 Device Management
Note 1: The MP-124 24-port, MP-108 8-port, MP-104 4-port and MP-102 2-port Media Gateways have
similar functionality except for the number of channels (the MP-124 and MP-102 support only
FXS), and all versions are referred to collectively in these release notes as the MP-1xx.
Note 2: MP-10x refers to MP-108 8-port, MP-104 4-port and MP-102 2-port Gateways.
Note 3: MP-1xx/FXS refers only to the MP-124/FXS, MP-108/FXS, MP-104/FXS and MP-102
/
FXS
Gateways.
Note 4: MP-10x/FXO refers only to MP-108/FXO and MP-104/FXO Gateways.
7.1 SNMP Management
7.1.1 SNMP Overview
SNMP (Simple Network Management Protocol) is a standard network-based client/server-based
control protocol to manage devices in the Network. The client program (called the Network
Manager) makes connections to a server program, called the SNMP Agent. The SNMP Agent,
embedded on a remote network device, serves information to the Network Manager regarding the
device's status. The database used by the Agent to retrieve information, is referred to as the
SNMP Management Information Base (MIB), and is a standard set of statistical and control
values. Apart from the standard MIBs documented in IETF’s RFCs, SNMP additionally allows the
usage of private MIBs, containing non-standard information set.
Directives, issued by the network manager client to an SNMP Agent, consist of the identifiers of
SNMP variables (referred to as MIB object identifiers or MIB variables) along with instructions to
either get the value for the identifier, or set the identifier to a new value.
The definitions of MIB variables supported by a particular agent are incorporated in descriptor
files, written in Abstract Syntax Notation (ASN.1) format, made available to network management
client programs so that they can become aware of MIB variables and their usage.
The MP-1xx contains an embedded SNMP Agent supporting both general network MIBs (such as
the IP MIB), VoP-specific MIBs (such as RTP, MGCP, etc.) and a proprietary MIB (known also as
AudioCodes MIB) enabling a deeper probe into the inter-working of the Gateway. All the
supported MIBs files are supplied as part of the release.
7.1.2 SNMP Message Standard
Four types of SNMP messages are defined:
" "Get" Request that returns the value of a named object.
" "Get-Next" Request that returns the next name (and value) of the "next" object supported
by a network device given a valid SNMP name.
" "Set" Request that sets a named object to a specific value.
" "Trap" Message generated asynchronously by network devices. It notifies the network
manager of a problem apart from polling of the device.
Each of the following message types fulfills a particular requirement of network managers:
" Get Request: Specific values can be fetched via the "get" request to determine the
performance and state of the device. Typically, many different values and parameters can be