Caller ID for FXO and T1-CAS on MGCP Gateway

[gglynn]

I'm curious, is there a serious technical limitation preventing the implementation of Caller ID (CLID) delivery to CallManager from FXO and T1-CAS trunks on MGCP gateways, or is it just that it simply hasn't been implemented yet?

[Hin Lee]

CLID/ANI is supported on FXO-M1 and FXO-M2.

FGD (Wink-start with wink-acknowledge or double-wink - A second wink that is sent to acknowledge the receipt of the DNIS information) is the only variant of T1 CAS that supports ANI and Cisco supports it along with the FGD-EANA variant. In addition to FGD functionality, FGD-EANA provides certain call services, such as emergency (USA-911) calls. With FGD, the gateway supports the collection of ANI inbound only. see http://www.cisco.com/en/US/tech/tk652/tk653/technologies_tech_note09186a00800e2560.shtml

[gglynn]

I know it's supported on the hardware, but CLID/ANI information received on FXO or T1 CAS trunks on a voice gateway isn't delivered to CallManager if the gateway is integrated with CallManager via MGCP. You can configure the gateway as an H.323 gateway and get the information into CallManager, but you can't do it with MGCP. My question is, "why?"