Cisco Systems OL-14619-01 Supported SIP Integrations, Cisco Unity Failover with SIP Trunks, 6-23

Chapter 6 Integrating Cisco Unity with the Phone System

Integrating by Using SIP

•A unique SIP address, which is similar to an e-mail address and uses the format sip:<userID>@<domain>. The user ID can be either a user name or an E.164 address.

When a user initiates a call, a SIP request typically goes to a SIP server (either a proxy server or a redirect server). The request includes the caller’s address (From) and the address of the called party (To).

SIP messages are in text format using ISO 10646 in UTF-8 encoding (like HTML). In addition to the address information, a SIP message contains a start-line specifying the method and the protocol, a number of header fields specifying call properties and service information, and an optional message body which can contain a session description.

Supported SIP Integrations

Cisco Unity currently supports the following SIP integrations:

•SIP trunks to selected versions of Cisco Unified Communications Manager and Cisco Unified Communications Manager Express. For a list of Cisco Unified CM and Cisco Unified CM Express versions supported as SIP trunks, see SIP Trunk Compatibility Matrix: Cisco Unity and Cisco Unified Communications Manager at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_device_support_tables_list.ht ml.

•Cisco SIP Proxy Server (CSPS). However, CSPS is being phased out, so using it for a SIP integration is not encouraged.

Third-party SIP trunks are currently not supported.

For more information on configuring SIP trunks between Cisco Unity and Cisco Unified CM or Cisco Unified CM Express, see the applicable SIP trunk integration guide at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_installation_and_configuration_g uides_list.html.

Cisco Unity Failover with SIP Trunks

Cisco Unity failover is not supported with either the Cisco Unified CM SIP trunk integration or the Cisco Unified CM Express SIP trunk integration. If Cisco Unity failover is a requirement, you must use the Skinny Call Control Protocol (SCCP) integration with Cisco Unified CM. A customer can continue to use SIP phones when integrating with Cisco Unified CM using the SCCP integration. Once a call is established between a SIP phone and Cisco Unity, which is using Skinny, the RTP session between the two endpoints will work properly.

Note that Cisco Unity failover is not supported for Cisco Unified CM Express using either the SIP trunk integration or SCCP integration.

SIP Compliance

For information on Cisco Unity compliance with the SIP standard, see SIP Compliance for Cisco Unity at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/prod_white_papers_list.html.

	Design Guide for Cisco Unity Release 5.x
OL-14619-01		6-23