<div>Hi Guys,</div><div><br></div><div>Just thought I would throw this out there, if any one has any advice, much appreciated. I'll probably go with a tac case shortly :)</div><div><br></div><div>I have 2 x CME-SRST routers at Site 1 - each router terminates an ISDN PRI circuit.</div>
<div>Phone 1 - registered to CME-SRST Router 1 at Site 1</div><div>Phone 2 - registered to CUCM v6.1(5) at Site 2</div><div>WAN Router 1 at Site 1 connects to WAN Router 2 at Site 2 via Ethernet link.</div><div>WAN Router 2 is configured as a H323 gateway in CUCM</div>
<div>WAN Router 1 and 2 are configured as IP to IP voice gateways</div><div><br></div><div>Dial peer is configured from both CME-SRST routers which points to WAN Router 1</div><div>WAN Router 1 then has dial peer that points to WAN Router 2</div>
<div>WAN Router 2 has a dial peer that points to CUCM</div><div>This part of the call flow works correctly, I can dial Phone 2 directly through both ISDN PRI's</div><div><br></div><div>Exact problem I have is as follows;</div>
<div>Inbound call on PRI connected to CME-SRST Router 2 to Phone 1</div><div>Routed via H323 dial peer to CME-SRST Router 1 and connected to Phone 1 succesfully</div><div>Phone 1 attempts blind xfer to Phone 2</div><div>
Phone 2 rings and the call seems connected</div>
<div>A few seconds of dead air</div><div>Then disconnection with ISDN disc conn cause of Resource Unavailable</div><div><br></div><div>If the call originates on Router 1 ISDN to Phone 1 - the transfer is fine.</div><div>
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</div><div>CME Routers are 3845 12.4(15)T13</div><div>The two wan routers also running the same code. A 3640 and 2811.</div><div><br></div><div>I have allowed H323 to H323 connections on all routers</div><div>I have enabled EmptyCapabilitySet on all routers</div>
<div>I have enabled H450.12 supp services on all routers</div><div>I have enabled H323 slow start on all routers</div><div>I have disabled "Wait for far end H.245" on the H323 gateway in CUCM. (Without this - Phone 2 rings and I answer it but the originating phone continues to play ring back unaware Phone 2 has been picked up)</div>
<div>Also tried H225 connect pass through</div><div>WAN Router 2 should have a SW MTP and HW Transcoder resource available.</div><div>I did try to force MTP for this.</div><div>Codec is G.729</div><div><br></div><div>I know it seems like a complex setup, so I am also trying to think of ways to simplify it.</div>
<div>The reason it goes through the 2 x WAN routers as IP to IP and not directly to CUCM from either CME router - is to enforce a max - number of calls across this link.</div><div>It is a backup only scenario.</div><div>
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</div><div>I have some ideas I am working through, but would be very open to any others!</div><div><br></div><div>One thing that crossed my mind, is would SIP be a better alternative for the routing. Maybe it is better equipped to handle all the transfers / back to backing.</div>
<div><br></div><div>Cheers,</div><div><br></div><div>Tim</div>