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Ieee 802.1d and 802.1q, Qos -20, Ieee 802.1d and 802.1q -20 – Avaya 4600 Series User Manual

Page 50

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4600 Series IP Telephone LAN Administrator’s Guide

QoS

4-20

#GETAPP
IF $MODEL4 SEQ 4630D01A GOTO SCREENSETS
IF $MODEL4 SEQ 4624D01A GOTO BIGSETS
IF $MODEL4 SEQ 4612D01A GOTO BIGSETS
IF $MODEL4 SEQ 4606D01A GOTO SMALLSETS

#SCREENSETS
SET APPNAME 4630_000301.BIN
GOTO END

#BIGSETS
SET APPNAME 4624_000301.BIN
GOTO END

#SMALLSETS
SET APPNAME 4606_000301.BIN

#END
GET 46XXSETTINGS.SCR

QoS

4

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

4

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)