Network design
302 Avaya Application Solutions IP Telephony Deployment Guide
802.3af specifications) that provides centralized power over pins 7 and 8 using a special cord
with over-current protection, and alarm LEDs for each output. The 1145B uses a locking station
cord to guard against damage, compared to the signature detection method of the IEEE Draft
802.3af specifications.
WAN
Because of the high costs and lower bandwidths available, there are some fundamental
differences in running IP Telephony over a WAN versus a LAN. Because of the resource
scarcity, it is important to consider network optimizations and proper network design, because
problems are more likely to manifest themselves in a WAN environment.
Topics covered include:
Overview
Frame Relay
Overview
The overview section covers:
●
QoS
●
Codec selection and compression
●
Serialization delay
●
Network design
QoS
In particular, QoS becomes more important in a WAN environment than in a LAN. In many
cases, transitioning from the LAN to the WAN reduces bandwidth by approximately 99%.
Because of this severe bandwidth crunch, strong queuing, buffering, and packet loss
management techniques have been developed. These are covered in more detail in the
Quality
of Service guidelines
chapter.
Recommendations for QOS
In general, for the WAN, Avaya recommends tagging IP Telephony bearer and signaling
packets with DiffServ Code Point (DSCP) 46 (Expedited Forwarding). This tagging can be
administered in Avaya IP Telephones, Communication Manager, and circuit packs. At the
routers, Avaya recommends using strict priority queuing for voice packets, and weighted-fair
queuing for data packets. Voice packets should always get priority over non-network-control
data packets. This type of queuing is called Class-Based Queuing (CBQ) on Avaya data
networking products, or Low-Latency Queuing (LLQ) on Cisco routers.
Содержание Application Solutions
Страница 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Страница 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Страница 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 74: ...Avaya Application Solutions platforms 74 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Страница 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 214: ...Voice quality network requirements 214 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 239: ...Reliability Issue 3 4 1 June 2005 239 Figure 69 S8700 Media Server in a high reliability configuration ...
Страница 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Страница 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 350: ...Implementing Communication Manager on a data network 350 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Страница 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Страница 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...