Failed call transfer on UC500

[sam2000]

Hello, I am using a UC540 as a small PBX.

Connected to the system the extensions are a mix of FXS phones, VoIP phones and ISDN phones.

I can call between extensions without issues and I can make or receive calls from SIP trunks. But somehow I can successfully transfer calls only from a VoIP phones.

Let me explain, any call received from a VoIP extension (unregarding from which other extension type or SIP trunk) with R or FLASH key can be put on hold, consultation with another number takes place, when hanging up on the VoIP extension the call is actually transferred to the number consulted before.

The same procedure with a call received by an FXS extension seems working until the consultation, however fails when hanging up and instead of transferring the call just drop every number involved.

The same procedure with a call received by an ISDN extension is even worse, just pressing the R key drops the first caller and don't let you start consulting anybody.

I am attaching my current configuration, I hope somebody could help me shed some light on this issue.

Thanks,

Paolo

[Nithin Eluvathingal]

Firstly, note that the UC540 reached its End of Life (EOL) on January 31, 2017. It’s crucial to transition to a Cisco Unified Communications Manager Express (CME) deployment promptly. As an alternative to the FLASH soft key, consider using the Transfer softkey for call handling. Verify if this approach aligns with your expectations.

Keep in mind that the FLASH soft key is primarily used to manipulate the CO (Central Office) line and is especially relevant for Centrex-enabled systems. However, it is not intended for transferring calls within the UC500 system itself.

[sam2000]

Hi Nithin, I know the UC500 is EOL but that's what I have. As for using FLASH or Transfer key, well I use what's available on the IP phone, one has only the flash key the other only transfer, but that's not my problem, transferring calls with the ip phone (which btw are all sip phones, not scm) does work, the issue arise when I try to transfer the call from a phone that is not ip... such as analog on fxs line or isdn on the bri line.

I think there's a config issue that makes the call being transferred drop but I can't understand what it could be.

thanks

Paolo