Cisco Cisco Customer Voice Portal 8.0(1) Design Guide
4-5
Cisco Unified Customer Voice Portal (CVP) 8.x Solution Reference Network Design (SRND)
OL-15989-06
Chapter 4 Designing Unified CVP for High Availability
SIP Proxy
interface Loopback0
ip address 10.0.0.10 255.255.255.255
h323-gateway voip interface
h323-gateway voip id sj-gk ipaddr 10.0.1.100 1719 <<- GK IP
h323-gateway voip h323-id sj-gw1
h323-gateway voip bind srcaddr 10.0.0.10
SIP:
voice service voip
sip
bind control source-interface Loopback0
bind media source-interface Loopback0
This configuration allows call signaling to operate independent of the physical interfaces. In this
way, if one interface fails, the other interface can handle the traffic. Each gateway interface should
be connected to a different physical switch to provide redundancy in the event that one switch or
interface fails. Each interface on the gateway is configured with an IP address on a different subnet.
The IP Router(s) for the network is then configured with redundant routes to the Loopback address
through the use of static routes or a routing protocol. If a routing protocol is used, pay careful
attention to the number of routes being exchanged with the gateway, and consider using filters to
limit the routing updates so that the gateway is only advertising the loopback address and not
receiving routes.
way, if one interface fails, the other interface can handle the traffic. Each gateway interface should
be connected to a different physical switch to provide redundancy in the event that one switch or
interface fails. Each interface on the gateway is configured with an IP address on a different subnet.
The IP Router(s) for the network is then configured with redundant routes to the Loopback address
through the use of static routes or a routing protocol. If a routing protocol is used, pay careful
attention to the number of routes being exchanged with the gateway, and consider using filters to
limit the routing updates so that the gateway is only advertising the loopback address and not
receiving routes.
Call Disposition
If the originating gateway fails, the following conditions apply to call disposition:
•
Calls in progress are dropped. There is nothing that can be done to preserve these calls because the
PSTN switch has lost the D-channel to all T1/E1 trunks on this gateway.
PSTN switch has lost the D-channel to all T1/E1 trunks on this gateway.
•
New calls are directed by the PSTN carrier to a T1/E1 at an alternate gateway, provided the PSTN
switch has its trunks and dial plan configured to do so.
switch has its trunks and dial plan configured to do so.
SIP Proxy
A SIP Proxy server plays a similar role to the gatekeeper in a Unified CVP solution. The SIP Proxy
server provides dial plan resolution on behalf of SIP endpoints, allowing dial plan information to be
configured in a central place instead of statically on each SIP device. A SIP Proxy server is not required
in a Unified CVP solution, but it is used in most solutions because of the benefits of centralized
configuration and maintenance. Multiple SIP Proxy servers can be deployed in the network to provide
load balancing, redundancy, and regional SIP call routing services. In a Unified CVP solution, the
choices for SIP call routing are:
server provides dial plan resolution on behalf of SIP endpoints, allowing dial plan information to be
configured in a central place instead of statically on each SIP device. A SIP Proxy server is not required
in a Unified CVP solution, but it is used in most solutions because of the benefits of centralized
configuration and maintenance. Multiple SIP Proxy servers can be deployed in the network to provide
load balancing, redundancy, and regional SIP call routing services. In a Unified CVP solution, the
choices for SIP call routing are:
•
SIP Proxy Server
–
Advantages:
Weighted load balancing and redundancy.
Centralized dial-plan configuration.
SIP Proxy may already exist or be used for other applications for dial-plan resolution or
intercluster call routing.
intercluster call routing.
–
Disadvantages:
Additional server and/or hardware required for SIP Proxy if not already deployed.