IP addressing
Issue 3.4.1 June 2005
291
DHCP
Dynamic Host Configuration Protocol (DHCP) is a tool that automates the assignment of IP
addresses. DHCP is a successor of BOOTP, the Bootstrap Protocol. Avaya IP Telephones can
use DHCP to learn their IP addresses, default gateways, call controller, tftp server, QoS
settings, and other parameters.
DHCP is a broadcast protocol. which means that request messages from DHCP clients such as
Avaya IP Telephones are seen by all devices on the local network, but are not forwarded to
additional subnetworks. If the DHCP server is present on a different network, DHCP forwarding
must be enabled on the router. DHCP forwarding converts the broadcast message into a
unicast message, and forwards the message to the configured DHCP server. DHCP forwarding
is offered on most routers and layer 3 switches, including those offered by Avaya and Cisco.
For more information, see
DHCP / TFTP
or the Avaya IP Telephone LAN Administrator’s Guide.
Recommendations for IP Telephony
Avaya recommends using a separate subnetwork for voice. Isolating voice traffic from data
traffic allows protection from viruses, excessive broadcast traffic, and security threats that are
caused by malicious users or external intruders. For most IP Telephony implementations, using
RFC 1918 (private) address space is acceptable. Generally, Voice over IP (VoIP) is not
deployed across the public Internet. Therefore, providing addresses in the private range saves
public IP addresses, and provides a layer of security protection by denying connections directly
in from the Internet. Should a public Internet connection prove necessary, Avaya recommends
setting up a C-LAN and a Media Processor card in a demilitarized zone (DMZ) off the firewall,
and using Communication Manager as a proxy server between the internal and external
networks.
Avaya also recommends using DHCP to configure IP Telephones. Using DHCP reduces
administration to a single point, and reduces the incidence of typographical errors that could
cause configuration problems. Avaya includes special configuration options for IP Telephones in
Option 176. Microsoft and ISC (Linux and Unix) DHCP servers support this option. Additional
methods exist for configuring IP Telephones if a particular DHCP server does not support
Option 176. Contact your Avaya representative for more information.
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 ...