User's Manual

Page 494 of 910 Configuration of IP Telephony nodes using OTM 2.2
553-3001-365 Standard 4.00 August 2005
2 802.1Q enables virtual LANs (VLANs) to be defined within a single LAN.
This improves bandwidth management and limits the impact of broadcast
and multicast messages.
Configure the 802.1Q settings as follows:
a. Enable 802.1Q support: Select the check box to enable 802.1Q
support. By default, 802.1Q support is disabled.
b. Priority 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.
Note: These values are applied to all Voice Gateway Media Cards in the
node.
3 Under DiffServ Codepoint, modify the DSCP Control and Voice values
only as directed by the IP network administrator.
The recommended configuration values are:
a. Control packets: A value of 40 – Class Selector 5 (CS5). This sets
the priority of the signaling messaging.
b. Voice packets: A value of 46 Control DSCP – Expedited Forwarding
(EF).
The DSCP determines the priorities of the management and voice
packets in the IP Line network. The range for both management and
voice packet DSCP is 0 – 63 inclusive.
The DSCP 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 DSCP from the default values unless instructed.
4 Click Apply and then click OK.
Note: As described on the QoS tab, NAT and QoS parameters are no
longer configured here. Therefore, those areas are grayed out.
End of Procedure