H323 call preservation

[ciscoforum]

There is a new command "call preserve" can help keep H323 call if tcp connection to CCM lost. The entire command is:

voice class h323 1

h225 timeout tcp establish 5

call preserve

What's the difference between the old way, which can also keep the h323 call up.

voice service voip

h323

no h225 timeout keepalive

[gogasca]

Coice class h323 => "call preserve" was added to 12.4(4)XT, which will also be available in 12.4(9)T this summer. This

works in conjunction with the "Allow Peer to Preserve H.323 calls" service parameter added into CCM 4.1(3)sr2 (es35) and above.

Prior to Call preserve, limited preservation was provided with "no h225 timeout keepalive" in IOS. That parameter had some holes in it...particularly in scenarios involving calls where only one side loses

connectivity to CallManager, and the other side receives a disconnect message. For example, a central IP Phone connected through a remote gateway, if the remote gateway loses connectivity to CallManager, the central phone may still receive a call clearing. Apart than no h225 timeout keepalive is not fully supported.