CiscoFeaturesTrends and thoughts

Revisiting Cisco Gateway Recording

By November 7, 2014 No Comments

Cisco logoIn Verba 8, we are also advancing our Cisco gateway recording support. Since it was introduced in Verba 7.0. a high level of performance and stability improvements have followed; above all, we have gained live operational experience in the last 18 months. A quick overview is due.

How does Cisco support voice gateway recording?

Historically Cisco phones included a recording support technology, sometimes referred to as media forking, BiB (built-in-bridge) or DMS (duplicate media stream) recording. These three are exactly the same: the phone sends a secondary Real-Time Transport (RTP) stream of the calls to a recorder.

Today Cisco gateways are providing similar media forking features, creating one or multiple audio and video streams associated with a single call and sending those different recording destinations. This processes is completely transparent for the end-users.

Two different Cisco product lines support gateway recording:

  • Integrated Services Router (ISR G2) enterprise grade gateways
  • Aggregation Services Router (ASR) service provider gateways

Your router needs to be equipped with the unified communication technology package configured as a CUBE in Real-Time Transport (RTP) flow through mode.

About the Verba recording integration with Cisco ISRG2 or ASR

Verba can offer multiple recording approaches based on the capabilities of the gateway and the expected call scenarios:

  • WSAPI based recording – this is an HTTP/SOAP based API which makes it possible to implement custom call control like call redirection, blocking and call monitoring. Verba recorders can subscribe to this interface and requests media stream. The interface makes possible to record any combination of SIP, H.323 and TDM/ISDN calls even if the call from PSTN is routed back to PSTN.
  • CUBE based recording – Cisco also offers a SIP based RTP forking interface on CUBE to record SIP-SIP call legs. This interface has advantages over WSAPI:
    • High Availability – both recorder failover and load-balancing is supported
    • Video recording -RTP forking based video recording available since IOS 15.3.3(T)
  • UCM 10 recording support – Since Cisco Unified Communication Manager 10.0 the phone-based BiB recording interface (in Verba terminology Cisco Central Recording) was seamlessly extended with gateway based forking as well. UCM automatically selects the most optimal recording source (phone or gateway) based on call flow scenario, network and media requirements. Restriction: gateway protocol must be SIP to use gateway forking and in UCM 10 there is no video recording support. Involving the gateway in Central Recording has the following advantages:
    • PSTN – PSTN calls (call from PSTN routed back to PSTN) can be recorded (Cisco Mobility / Single Reach)
    • Calls on recorded phones without BiB support are automatically routed through gateways
    • Failover-based high availability is supported

Selecting your Cisco gateway recording approach

If you are using UCM 10, the best option maybe to go with the native network-based recording support, unless you need to record video or non unified mobility PSTN-PSTN calls (ex. recorded party is not a single reach number: recorded PSTN party calls, non-recorded internal, inbound call forwarded/transferred to recorded PSTN number directly).

If you are using versions before 10 or you need to record video calls:

  • if you need to record only PSTN inbound and outbound calls, simple gateway based recording is an ideal solution. This way you can record calls from PSTN routed back to PSTN in various types of PSTN side protocols (SIP, H.323, TDM/ISDN). This scenario happens if Cisco Mobility is in use and your users may answer call on their mobiles. The same happens when you are recording Jabber mobile calls.
  • if you also need internal calls, you can turn on our phone device-based standard central recording technology, but you need to accept that some calls might be recorded twice

There are lot more possibilities with multiple sites, site failover and load-balancing, if you would like further information, please contact one of our experts today.