Description; Ip Phone Support - Nortel 1110 Fundamentals

462 Appendix B 802.1Q VLAN description
The 802.1Q support is configured from the user display interface of the IP
Phone. Configure 802.1Q VLAN support when you initially configure an IP
Phone. The switch ports for Voice Gateway Media Card TLAN network
interfaces must be configured as untagged ports so the header is removed.
While the IP Phone 2001 and the IP Audio Conference Phone 2033 provide
VLAN support, they do not provide a port for a PC.
The 802.1Q IEEE protocol standard allows virtual LANs (VLANs) to be
defined within a single LAN. This improves bandwidth management and
limits the impact of broadcast and multicast messages. A higher level of
security between segments in a network can also be achieved.
802.1Q functionality is supported only on the IP Phone. The IP Line
application IP stack does not provide 802.1Q support for the Voice Gateway
Media Card.

Description

The p bits within the 802.1Q standard allow packet prioritization at Layer 2
improving network throughput for VoIP data.
The 802.1Q standard specifies a new format of Ether net frame. A standard
Ethernet frame contains
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The 802.1Q formatted frame is identical to a standard Ethernet frame, with
the exception of the 4-byte 802.1Q tag that is inserted between the source
MAC address and the protocol identifier. The first 16 bits of the 802.1Q
tag field is the Tag Protocol Identifier containing 8100 (hex), allowing the
Ethernet interface to distinguish it from standard Ethernet frames. The last
16 bits of the 802.1Q tag contain the following information
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IP Phone support

The IP Phones support 802.1Q as follows
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Copyright © 2003–2007, Nortel Networks
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a header consisting of a six-byte destination MAC address (following
the header is a data area)
a six-byte source MAC address
a two-byte protocol identifier
a 3-bit Priority field (the 802.1p defined bits)
a 1-bit Canonical Field Identifier (CFI)
a 12-bit VLAN ID field
802.1Q can be enabled or disabled at boot time using manual
configuration or control downloaded from the TPS.
If 802.1Q is disabled, standard Ethernet frames are transmitted.
Nortel Communication Server 1000
IP Phones Fundamentals
NN43001-368 02.01 Standard
Release 5.0 7 December 2007