Does Media flow around still passes the RTP through CUBE

[nawaz.pasha]

Let's say Ex: if I have Phone A >>> CUCM A >>> CUBE >>>CUCM B >> Phone B

As we know that we have media flow-through and media flow around.

Since, in media-flow through we know that RTP goes through CUBE and with flow around media(RTP) happens from phone to phone...but how that works....in reality if the devices has to go through CUBE to connect if they both are on the different networks...

Can anyone explain this flow around for the RTP...I know the signal still go through cube in both cases...just the RTP in question which has the direct connection from A <> B..how phone itself will communication without the CUBE...if no other connectivity exists in flow around case

[Atul Gaba]

There has to be connectivity between the endpoints if using media-flow around for the RTP to flow.

-Atul

[nawaz.pasha]

My question is only CUBE is present between the two end points registering to CUCM between two CUCM...How the scenario works for the flow around...Since, flow around shouldn't pass through the media so there is no way to escape if no other alternate way to connect the media around so, how the CUBE will treat this traffic...it just passes the traffic without interference in that scenario..

Two end point can't just talk in the air wirelessly someone has to connect them so, if CUBE is the only device how this media flow around works...that's my question

[Jitender Bhandari]

Check the below links and let me know if you have specific questions.

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/media-path.html

https://supportforums.cisco.com/discussion/12163086/cube-media-flow-through-vs-media-flow-around

HTH

JB

[devils_advocate]

"how phone itself will communication without the CUBE"

They are both network devices so they will communicate like any other network device.

RTP packets will be routed from Endpoint A to Endpoint B at Layer 3. 

"if no other connectivity exists in flow around case"

It would be very odd for the configuration to be exactly like the one above, the CUCM servers would not be plugged into the CUBE directly, they and the CUBE would be part of a bigger routed network.

[nawaz.pasha]

In both cases Flow-through and Flow-around your signalling will be dealt by CUBE if the CUBE is the only device present between A & B no other Router(L3 device present to transfer the traffic). If CUBE is the bridge to connect Phone A & B.

However, this particular question related to media which is your RTP stream(UDP) traffic which is again UDP IP packet and CUBE will replace the port to its own ip:port in case of flow-through and flow around it acts as a transparent bridge it won't look or modify anything in flow-around case. CUBE is a layer 7 device and Router is layer 3 device which only looks for IPs. So, CUBE acts as a Layer 3 device(flow-around) if this is the only device b/w A<>B . Cube is not a layer 7(SIP) and Layer 4(RTP). Hope this helps. Also in case where RTP don't need to route the traffic via CUBE it just uses other L3 Routers for RTP traffic in case of flow-around.