Hi all,
I searched many post in our forum but not work.My customer scope:
PSTN -> E1 -> 2921 VGW -> H323 -> CUCM 8.5 -> CTI Route Point -> Transfer to End Device (ringback ok).
PSTN -> Sip trunk -> 3845 VGW -> H323 -> CUCM 8.5 -> CTI Route Point -> Transfer to End Device (no ringback).
PSTN -> Sip trunk -> 3845 VGW -> H323 -> CUCM 8.5 -> End Device (ringback ok) -> Transfer to another End Device (no ringback).
Configure 2921 VGW and 3845 VGW on CUCM have some differences: 3845 Enable Inbound FastStart, Media Termination Point Required but same MRGL(because it connect to PSTN via SIP Trunk, if i disable this, call cannot connect). Between VGW, Server, end device don't have any firewall.
I think this problem is blind transfer in Sip trunk.
My question:
- Ringback is always generate by Annunciator device CUCM, is that true? Or it can generate by VGW ? How to check this? I can capture packet log on CUCM and end device, cannot capture on VGW.
- Call Transfer will using Re-invite? Maybe it's don't work correctly in SIP Trunk (with another provider) ?
- How to fix this? (Most important).
Because this is the system of my customer, i cannot get log easily. Please think all of log you can and i take this once or two time :(
You can take me many solutions, i will try all and response which one help me.
Thanks,
Thanh Duy Tran
