Cisco Cisco Unified Customer Voice Portal 11.0(1)

Server to be preferred
over the other.

Gateway will not answer
the call from the PSTN.

If the selected endpoint
either does not respond

The SIP Proxy Server is
configured via a static

New Call from SIP Proxy Server to Call Server (SIP Service)

within a time-out period,

route table with all SIP

or responds with a

Service endpoints; each

500-level message to

endpoint also has a

reject the call, the SIP

preference value. The

Proxy Server will try the

Proxy Server selects the

next most preferred

endpoint with the highest

endpoint in its static route

preference value, or will

table. If no endpoint

round robin among

accepts the call, the SIP

endpoints with the same
preference value.

Proxy Server rejects the
call by returning a
500-level message to the
Ingress Gateway. The SIP
Service may also reject
the call if other required
components in the same
Call Server will not be
able to perform their
tasks.

If the selected SIP Service
either does not respond

Multiple Call Servers can
be configured using

New Call from Ingress Gateway to Call Server (SIP Service) [for
deployments which do not use a SIP Proxy Server]

within a time-out period,

successive dial peers on

or responds with a

the gateway and varying

500-level message to

preference values. The

reject the call, the Ingress

Ingress Gateway selects

Gateway will try the next

the Call Server with the

most preferred endpoint

highest preference value,

according to its dial-peer

or will round robin among

configuration. If no Call

endpoints with the same
preference value.

Server accepts the call,
the Ingress Gateway will
not answer the call from
the PSTN. (Note: This is
a trial-and-error type of
failover.) The time-out
period is configurable in
the IOS configuration for
SIP User Agent—it is the
"expires" timer value.

The VRU PG can be
deployed in pairs. If one

Pre-established
relationship. If this static

New Call from Call Server (SIP Service) to VRU PG

side goes down, the other

connection is not

side immediately creates

operational, the SIP

Planning Guide for Cisco Unified Customer Voice Portal Cisco Unified Customer Voice Portal 4.1(1)