Why cisco CUBE permits RTP traffic w/o explicit rule?

[Ivanleonel]

Hi,

Running a couple CME+CUBE I noticed that the only traffic required to be permitted in ACL is SIP protocol – UDP:5060.

Why on earth, a router permits RTP protocol without specific record in ACL?

[Dennis Mink]

Ivan,

by default, the CUBE has no ACLs on any of its interfaces. so it should allow RTP.

the other options is the CUBE working in flow around mode, where the RTP stream is end to end between the endpoints and the CUBE is NOT ins the path. (this is not the default, the default is flow through, where CUBE is in the path.)

issue show call act voice compact to find out which is used.

cheers

Please rate if useful

[Ivanleonel]

Hi Dennis,

Sorry for my delayed reply I‘m quite busy these days.

I’m using ACL on outside interface and there is no permissions for RTP. Also I’m not using SIP inspection. Besides CBAC inspection works only for pass-through traffic and not for router originated traffic.

My CUBE+CME router the only termination point for media and signaling traffic.

#show call act voice compact

 <callID>  A/O FAX T<sec> Codec       type        Peer Address       IP R<ip>:<udp>

Total call-legs: 2

     54898 ANS     T14    g711ulaw    TELE        P131

     54899 ORG     T14    g711ulaw    VOIP        Pxxxxxxxxxx   85.45.45.45:18244