CUBE base configuration

[Gramirez23]

Dear Fellows

We want to put a Cube between a Sip Telephony Service Provider  and a Call Manager, and i read tons of guides to configuring, but im really confused, my question is, there is a recomended step by step configuration to do so?, we want basic outbound and inbound telephony with dtmf passing.

And another question, what is the difference between implement CUBE as flow around or flow throught ? when is appropiate put one instead of another?

Thanks in advance

[Senthil Kumar Sankar]

Hi Gramire,

In order to Configure CUBE in Cisco IOS Voice Gateway, You nee to have below configured under voice service voip

voice service voip
mode border-element
allow connections sip to sip

Media Flow thru :

     RTP Media Packets will be flowing through the CUBE

Media Flow Around :

     RTP Media Packets will be flowing around(not through the Cube endpoint to endpoint)

Regards,

Senthil

[Gramirez23]

Thanks for the answer

That's is the basic config, to tell the router "acting like a CUBE", right?, i assume that we have to create dial-peers after this.

And i like to know the difference between flow thru and flow around at technical level, mean, when is good to use one instead of another

Thanks

[acampbell · Accepted solution]

Hi,

take a look at this Q & A url

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6790/gatecont/ps5640/prod_qas09186a00801da69b.html

Q. What do "flow around" and "flow through" mean?

A. The terms describe whether the Real-Time Transport Protocol (RTP), or media, traffic from the originating and terminating endpoints flows through the Cisco Unified Border Element or flows around it (directly from endpoint to endpoint).

Advantages of flow-through mode include the obscuring of endpoint RTP port numbers and IP addresses, support for supplementary services, converting in-band dual-tone multifrequency (DTMF) relay such as RFC 2833 to out-of-band methods, and doing media manipulation such as transcoding. Flow-around support can reduce the CPU load on the Cisco Unified Border Element, but address hiding on RTP packets is no longer applicable, transcoding cannot be done, and some supplementary services may not be supportable.

Flow around for H.323-to-H.323 mode is supported as of Cisco IOS Software Release 12.3(1), and flow around for SIP-to-SIP calls is supported as of Cisco IOS Software Release 12.4(9)T.

HTH

Alex

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[Senthil Kumar Sankar · Accepted solution]

Hi Gramire,

Yes after enabling the CUBE Functionality, You have to create Inbound/Outbound Dial-peers as per your requirement.

Media Flow Thru/Media Flow Around is completely about SDP information on SIP

SDP will contain Media Information like Codec/Paylod/Media IP Address.

When you use MediaFlowThru type most of the time the Media IP Address on SDP would be same as your Signalling IP of your Cube (Cube blindly terminates and re-originates the RTP packets irrespective of the content type negotiated by both the ends. This supports address hiding and NAT traversal.)

When you use MediaFlowAround type the Media IP address on the SDP would be the end devices IP address(Cube doesnot terminates nor re-originates RTP packets. Media negotiation and media exchange is completely end-to-end.)

Regards,

Senthil

[Gramirez23]

Hi SenthilKumar

Perfectly clear, the last question is how do enable media flow around or flow thru on the CUBE?

Thanks and regards

[Senthil Kumar Sankar · Accepted solution]

Hi Gramire,

You can configure Media Flow thru/ Media Flow around in two ways.

1) Globally for Cube :

     voice service voip
            media flow-through

2) Dial-peer Basis :

     dial-peer voice 102 voip

          media flow-through

Regards,

Senthil

[Gramirez23]

Perfect

And if i don't put any commands related to media flow around or thru, what is the default behavior?

Regards

[Muthurani Lavanya Paneerselvam]

Alex & Senthil

Thanks for sharing. Appreciate your help.

[Pasha Teplitsky]

Hi,

A bit late but hopefully it will help others as well.

You can find a step by step guide here. You can also find in the same place the CUBE config utility to help you build a clean configuration.

Good luck!