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New Member

CUBE, Media Flow Through vs. Media Flow Around

So CUBE gives the ability to have either Media Flow-Through or Media Flow-Around.  I think I have a good handle on what the difference between the two is but what are some real-world reasons as to one would be preferred over another?

Everyone's tags (1)
Cisco Employee

Hi,Media flow through is used


Media flow through is used to support many of the features available like IP address translation and IP address hiding. Media flow around allows the CUBE greater scalability in the number of calls that can be processed by one CUBE router.




New Member

Hello Manish,I have to

Hello Manish,

I have to configure SIP to SIP trunking through CUBE.

Can you please help me in configuring it?

I need to allow SIP to SIP through the CUBE. I have to translate internal addresses when call will go out of the CUBE towards the destination through WAN. 

I am not able to understand about DTMF. Can you  please tell me about it?


Thanks and Regards,
Mukesh Kumar
Network Engineer
Spooster IT Services

Here is good document for

Here is good document for CUBE-CUCM configuration example created by TAC.


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New Member

Thanks for the information

Thanks for the information mohammed al baqari.

But I want to know about DTMF, I am confused in it.

As there are two types of DTMF,

1) In band 

2) Out band

When I am configuring CUBE so which type of band I have to use on which dial peer and why?


Mukesh Kumar
Network Engineer
Spooster IT Services

Hi, Inband DTMF relay means



Inband DTMF relay means that DTMF digits will be sent in the media path between endpoints using different RTP payload type to be distinguished from the actual media stream.

For example, G729 uses RTP PT as 18 while NSE DTMF relay uses by default RTP PT as 96.


Outband DTMF relay signals DTMF digits using the signaling protocol (H323, SIP, MGCP). This isn't typically used when SCCP phones are deployed as SCCP phones don't recognize inband DTMF (you MTP to get SCCP working with inband DTMF)

Some good links about DTMF types.

New Member

Thanks a lot mohammed al

Thanks a lot mohammed al baqari,

Please tell me one thing when we configure CUBE in that case it is compulsory to configure DTMF inband and outband on every dial-peer?


Is there any method through which DTMF will be pass through the CUBE?

Like CUCM send any DTMF that will reach CUBE device and CUBE will forward that DTMF without checking anything in it.


Mukesh Kumar
Network Engineer
Spooster IT Services

Hi,You can configure single


You can configure single DTMF relay type or multiple types (preferred) to fallback and match the type which suites the other party.


CUBE will always be setting in the media path as long as you are using media flow mode. In case you use media flow around with RTP NTE, then CUBE won't be inserted in the media path.


VIP Super Bronze

Good question.Media flow

Good question.

Media flow-around terminates the signaling stream and allows RTP streams to flow directly between endpoints.
F. Media flow-through provides address hiding by terminating both signaling and RTP streams.

Media flow through and media flow around mode is supported on the Cisco Unified Border Element (CUBE). The CUBE is always involved in the call setup (signaling) portion of the call, but the media (RTP bearer stream) may flow through the CUBE or be routed around the platform.

Media flow around allows the CUBE greater scalability in the number of calls that can be processed by one CUBE router.

For Media flow through option, the media packets are passed through the CUBE, they will get terminated and re-originates with CUBE’s IP address and port number, so here we cannot find the original gateway’s ip address. This is one of the security feature in the CUBE. The default option is “media flow-through”.

In real life I think it is down to scalability. The fact that media doesnt pass through CUBE in flow around means that CUBE can process more calls (CPU, memory etc)..

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