Quality of Service guidelines
316 Avaya Application Solutions IP Telephony Deployment Guide
IEEE 802.1 p/Q
Figure 82: 802.1Q tag
The IEEE 802.1Q standard is a Layer 2 tagging method that adds 4 bytes to the Layer 2
Ethernet header. IEEE 802.1Q defines the open standard for VLAN tagging. Two bytes house
12 bits that are used to tag each frame with a VLAN identification number. The IEEE 802.1p
standard uses 3 of the remaining bits in the 802.1Q header to assign one of 8 different classes
of service. Communication Manager users can add the 802.1Q bytes and set the priority bits as
desired. Avaya suggests that a priority of 6 be used for both voice and signaling. The Avaya line
of data switches can switch frames with or without these VLAN headers, with no configuration
time spent. IEEE 802.1p and IEEE 802.1Q are OSI layer 2 solutions, and work on frames.
Because 802.1Q is a Layer 2 (Ethernet) standard, it only applies to the Ethernet header. At
every Layer 3 boundary (router hop), the Layer 2 header, including CoS parameters, is stripped
and replaced with a new header for the next link. Thus, 802.1Q does not enable end-to-end
QoS.
Summary of Contents for Application Solutions
Page 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Page 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Page 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Page 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Page 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Page 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...