Nortel Networks NN43001-563 - Manual (Page 160)

160 ITG engineering guidelines
Priority routing for voice packets
Routers having the capability to turn on priority for voice packets should
have this feature enabled to improve QoS performance. If the Type of
Service (TOS) field or Differentiated Services (DiffServ) is supported on the
IP network, the decimal value of the DiffServ/TOS byte can be configured.
For example, a decimal value of 46 is interpreted in TOS as "Precedence
= Priority" and "Reliability = High"
CAUTION
Service Interruption
Do not change the DiffServ/ToS byte from the default value unless
directed by the network administrator.
Setting up the ELAN subnet
The ELAN subnet is a 10BaseT Ethernet subnet. Very little traffic is
generated by the IP Trunk 3.01 (and later) node on this network. Cards
generate this traffic when the cards are looking for the Active Leader after
a reset and when SNMP traps are emitted due to IP trunk card events
and errors.
The ELAN subnet can also carry functional signaling traffic for Symposium
Call Center Server (SCCS), Small Symposium Call Center (SSCC), or
CallPilot Multimedia Message Server. The ELAN subnet can be configured
on a Layer 2 switch to maximize data throughput.
How to avoid system interruption
Duplex mismatch
Duplex mismatches can occur in the LAN environment when one side is set
to auto-negotiate and the other is hard-configured. The auto-negotiate side
adapts to the fixed-side settings, including speed. For duplex operations,
the Auto-negotiate side sets itself to half-duplex mode. If the forced side is
full-duplex, a duplex mismatch occurs.
To hard-configure all devices for speed/duplex, ensure every device and
port is correctly configured in order to avoid duplex mismatch problems.
Nortel Communication Server 1000
IP Trunk Fundamentals
NN43001-563 01.01 Standard
Release 5.0 30 May 2007
Copyright © 2007, Nortel Networks
.