Qos; Ieee 802.1D And 802.1Q - Avaya 4600 Series Administrator's Manual

4600 Series IP Telephone LAN Administrator's Guide

QoS

The 4600 Series IP Telephones support both IEEE 802.1D/Q and DiffServ, and may in the future
support other, possibly proprietary, procedures for implementing Quality of Service. In addition,
other network-based QoS initiatives such as UDP port selection do not require support by the
telephones, but nonetheless can contribute to improved QoS for the entire network.

IEEE 802.1D and 802.1Q

IEEE's 802.1Q standard defines a tag that can be added to voice and data packets. Most of the
information associated with this tag deals with Virtual LAN (VLAN) management, but 3 bits are
reserved for identifying packet priority. These 3 bits allow any one of 8 priorities to be assigned to
a specific packet. As defined in the standard, the 8 priorities are, from highest to lowest:
7: Network management traffic
6: Voice traffic with less than 10ms latency
5: Voice traffic with less than 100ms latency
4: "Controlled-load" traffic (mission-critical data applications)
3: Traffic meriting "extra-effort" by the network for prompt delivery (for example, executives'
e-mail)
2: Reserved for future use
0: Traffic meriting the network's "best-effort" for prompt delivery (the default priority)
1: Background traffic such as bulk data transfers and backups
Priority 0 is a higher priority than Priority 1.
To support IEEE 802.1D/Q, the 4600 Series IP Telephones can be administered either from the
network, via appropriate administration of the DHCP or TFTP servers, or at the telephone itself, via
dialpad input. Specific implementation details for local administration are in the Installation
Manual, and for remote administration are in this chapter, in
and Application Files'' on page
telephones can be administered. These parameters are:
L2Q: setting the 802.1Q framing parameter ON or OFF
L2QAUD: setting the 802.1Q audio priority value (between 0 and 7, default is 6)
L2QSIG: setting the 802.1Q signaling priority value (between 0 and 7, default is 6)
The 4600 Series IP Telephones can simultaneously support receipt of packets using, or not using,
802.1Q parameters.
QoS
4-20
4-18. In summary, three IEEE 802.1D/Q QoS parameters in the
4
4
''4600 Series IP Telephone Scripts