Tommer Catlin Fri, 08/03/2007 - 09:40
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Do you still have the link for this? it's broken.


dford333 Sun, 08/05/2007 - 21:24
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yes you need to hairping the call

h323 - h323

voice service voip

supplementary-service h450.12

allow-connections h323 to h323


transfer-system full-consult

transfer-pattern .T

Cisco Unified CME VoIP Call Transfer Options

Your Cisco Unified CME system by default is set up to allow local transfers between IP phones only. It uses the Cisco H.323 call transfer extensions to transfer calls that include an H.323 VoIP participant.

To configure your Cisco Unified CME system to use H.450.2 transfers (this is recommended), set transfer-system full-consult under the telephony-service command mode. You also have to use this configuration for SIP VoIP transfers.

To configure your Cisco Unified CME system to permit transfers to nonlocal destinations (VoIP or PSTN), set the transfer-pattern command under telephony-service. The transfer-pattern command also allows you to specify that specific transfer-to destinations should receive only blind transfers. You also have to use this configuration for SIP VoIP transfers. The transfer-pattern command allows you to restrict trunk-to-trunk transfers to prevent incoming PSTN calls from being transferred back out to the PSTN (employee toll fraud). Trunk-to-trunk transfers are disabled by default, because the default is to allow only local extension-to-extension transfers.

To allow the H.450.12 service to automatically detect the H.450.2 capabilities of endpoints in your H.323 VoIP network, use the supplementary-services command in voice service voip command mode.

To enable hairpin routing of VoIP calls that cannot be transferred (or forwarded) using H.450, use the allow-connections command. The following example shows a call transfer configuration using trhe above command.

The configuration shown in the preceding example turns on the H.450.2 (transfer-system full-consult) and H.450.12 services, allows VoIP-to-VoIP hairpin call routing (allow-connections) for calls that don't support H.450, and permits transfers to all possible destinations (transfer-pattern). The transfer permission is set to .T to provide full wildcard matching for any number of digits. (The T stands for terminating the transfer destination digit entry with a timeout.)

The following example shows a configuration for more restrictive transfer permissions.


transfer-system full-consult

transfer-pattern 1...

transfer-pattern 2... blind

This example permits transfers using full consultation to nonlocal extensions in the range 1000 to 1999. It also permits blind transfers to nonlocal extensions in the range 2000 to 2999.


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