Avaya 4600 User Manual

Quality of Service (QoS) is a term covering several initiatives to maximize the voice quality 
heard at both ends of a call that originates or terminates on an IP-based telephone. These 
initiatives include various prioritization schemes to offer voice packets a larger or prioritized 
share of network resources. These schemes include standards such as:

●

IEEE’s 802.1D and 802.1Q, 

●

the Internet Engineering Task Force’s (IETF’s) “Differentiated Services,”

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RTP Control Protocol (RTCP), 

●

Resource ReSerVation Protocol (RSVP), and

●

port-based priority schemes such as UDP port selection. 

Documentation for your LAN equipment details the extent to which your network can support 
any or all of these initiatives. See 

on page 43, for some implications of 

QoS for the 4600 Series IP Telephones.

As of Release 1.7, both the 4620 and 4630 families of IP Telephones provided network audio 
quality information to the end user. This network audio quality information might be useful to the 
LAN Administrator. As of Release 1.8, all 4600 Series IP Telephones provide some level of 
detail about network audio quality. For specific information, see 

Simple Network Management Protocol (SNMP) is a family of standards-based protocols and 
procedures to allow vendor-independent data network management. Using a simple set of 
protocol commands, an SNMP-compliant device stores information in standard format in one or 
more Management Information Bases (MIBs). Usually, devices support the standards-specific 
MIB termed MIB-II. In addition, devices can define one or more “custom MIBs” that contain 
information about the device’s specifics.

As of Release 1.1, the 4600 Series IP Telephones are fully compatible with SNMPv2c, a later 
version of SNMP, and with Structure of Management Information Version 2 (SMIv2). The 
telephones respond correctly to queries from entities that comply with earlier versions of SNMP, 
such as SNMPv1. “Fully compatible” means that the telephones respond to queries directed 
either at the MIB-II or the Custom MIB. The 4600 Series IP Telephone Custom MIB is read-only. 
Read-only means that the values therein cannot be changed externally by means of network 
management tools.