voip call signaling needed or not

[sarahr202]

Hi everybody

Please consider the following example:             

1)  analogphone----Voice gateway/CME-------sw---------ipphones.

Above we are using a ISR which is acting as voicegateway and CME router.  Since  a single router is acting as voice gateway and CME router therefore we dont need call signaling protocols between Voicegateway and CME because these both function are performed by the same router. If we have one router as voice gateway and  another router as CME, we need call signaling protocols between these two routers.

Is my understanding correct ?

2)  analogphone2 ---voicegateway----------------Router CME---------sw-----iphphones.

Above we have configured voicegateway for analog phones. and Voicegateway is not controlled by Router CME.

Above we need a call signaling protocol between voicegateway and Router CME.

Is my understanding correct ?

thanks and have a great  day.

[Harmit Singh · Accepted solution]

Hi Sarah,

1>     Yes, that is correct to a certain extent. The CME is the voice gateway in this case. For the analog device, it is configured as a POTS device, whereas your IP Phone may be talking SCCP or SIP. So its the CME / gateway's job to allow this call to work provided your config is correct.

2>     Yes, that is correct as well. The call signaling protocol would depend on the type of dialpeer you use to send the call out towards the CME and vice versa (assuming there is a WAN / LAN connection between the 2). You could even have analog connectivity such as FXS to FXO or FXO to FXS, digital connection such as ISDN PRI - between the voice gateway and CME.

HTH.

Regards,

Harmit.