Table Of Contents

Session Refresh with Reinvites

Prerequisites

Restrictions

Configuring Session Refresh with Reinvites

Session Refresh with Reinvites

Configuring support for session refresh with reinvites expands the ability of the Cisco Unified Border Element to receive a REINVITE message that contains either a session refresh parameter or a change in media via a new SDP and ensure the session does not time out. The midcall-signaling command distinguishes between the way a Cisco Unified Communications Express and Cisco Unified Border Element releases signaling messages. Most SIP-to-SIP video and SIP-to-SIP ReInvite-based supplementary services features require the Configuring Session Refresh with Reinvites feature to be configured.

Cisco IOS Release 12.4(15)XZ and Earlier Releases

Session refresh support via OPTIONS method. For configuration information, see the "Enabling In-Dialog OPTIONS to Monitor Active SIP Sessions" section.

Cisco IOS Release 12.4(15)XZ and Later Releases

Cisco Unified BE transparently passes other session refresh messages and parameters so that UAs and proxies can establish keepalives on a call.

Prerequisites

•The allow-connections sip to sip command must be configured before you configure the Session refresh with Reinvites feature. For more information and configuration steps see the "Configuring SIP-to-SIP Connections in a Cisco Unified Border Element" section.

Cisco Unified Border Element

•Cisco IOS Release 12.4(20)T or a later release must be installed and running on your Cisco Unified Border Element.

Cisco Unified Border Element (Enterprise)

•Cisco IOS XE Release 2.5 or a later release must be installed and running on your Cisco ASR 1000 Series Router.

Restrictions

•SIP-to-SIP video calls and SIP-to-SIP ReInvite-based supplementary services fail if the midcall-signaling command is not configured.

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Note The following features function if the midcall-signaling command is not configured: session refresh, fax, and refer-based supplementary services.

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•Configuring Session Refresh with Reinvites is for SIP-to-SIP calls only. All other calls (H323-to-SIP, and H323-to-H323) do not require the midcall-signaling command be configured

•Configuring the Session Refresh with Reinvites feature on a dial-peer basis is not supported.

Configuring Session Refresh with Reinvites

To configure Session REfresh with Reinvites, complete the following task:

1. enable

2. configure terminal

3. voice service voip

4. sip

5. midcall-signaling passthru

6. exit

7. end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice service voip Example: Router(config)# voice service voip	Enters VoIP voice-service configuration mode.
Step 4	sip Example: Router(conf-voi-serv)# sip	Enters SIP configuration mode.
Step 5	midcall-signaling passthru Example: Router(conf-serv-sip)# midcall-signaling passthru	Passes SIP messages from one IP leg to another IP leg.
Step 6	exit Example: Router(conf-serv-sip)# exit	Exits the current mode.
Step 7	end Example: Router(conf-serv-sip) end	Returns to privileged EXEC mode.