Network design
310 Avaya Application Solutions IP Telephony Deployment Guide
reduce administrative overhead provides a powerful incentive. Most important, by helping
integrate voice and data communication, multimedia messaging, supplier and customer
relationship management, corporate data stores, and other technologies and resources,
converged networks promise to become a key enabler for eBusiness initiatives.
NAT
IP Telephony does not work well with networks that use NAT (Network Address Translation)
because most NAT implementations do not support H.323 protocols. The destination IP address
is encapsulated in more than one header, including the Q.931, H.225, and IP headers. NAT
changes only the address in the IP header, which results in a mismatch that prohibits the control
of calls. Avaya suggests using a firewall to guard against intruders, but the firewall should not
provide NAT functions for IP Telephony packets unless it is Avaya Q.931 friendly.
Figure 81: IP
Telephony without NAT
shows an approved sample implementation of a firewall that uses
selective NAT. With Avaya Communication Manager 1.3 and later, products work seamlessly
with many static NAT applications, even if they are not H.323 aware.
Figure 81: IP Telephony without NAT
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 ...