Page 386 of 910 Configuration of IP Telephony nodes using Element Manager
553-3001-365 Standard 4.00 August 2005
2The Differentiated Service (DiffServ) CodePoint (DSCP) value
determines the priorities of the management and voice packets in the IP
Line network. The range for both management and voice packet DiffServ
is 0 – 63 inclusive.
The DiffServ value can be configured, if required, to obtain better QoS
over the IP data network (LAN/WAN).
The value entered depends on the policy in the customer’s data network.
Note: Do not change DiffServ from the default values unless instructed
by the IP network administrator.
Only modify the Control packets priority and Voice packets priority values
as and when directed by the IP network administrator.
The recommended configuration values are as follows:
a. Diffserv CodePoint (DSCP) Control packets: A value of 40 - Class
Selector 5 (CS5). The range is 0 – 63. This configures the priority of
the signaling messaging.
b. Diffserv CodePoint (DSCP) Voice packets: A value of 46 Control
DSCP - Expedited Forwarding (EF). The range is 0 – 63.
3802.1Q enables Virtual LANs (VLANs) to be defined within a single LAN.
This improves bandwidth management and limits the impact of broadcast
storms and multicast messages.
a. Enable 802.1Q support: 802.1Q support is disabled by default.
b. 802.1Q Bits value (802.1p): The priority field is a 3-bit value, with a
default value of 6. The range is 0 – 7. A value of 6 is recommended
by Nortel. The p bits within the 802.1Q standard enables packet
prioritization at Layer 2, improving network throughput for IP
Telephony data.
End of Procedure