SBC feature on ASR1k have flexible, but maybe not easy to configure call routing policy mechanism. Many factors can be taken into consideration while deciding how call should be routed including time, category, prefix and you can even apply round robin fashion of call distribution. Let’s look at the simplest of possible call routing.
Read More
By default when register message passes SBC username in contact field is replaced with random string. This string identifies pinhole opened for particular user for management purposes. But this behavior is not always desirable. Many SIP implementations identifies user by Contact field and rewriting it with random string would prevent application from registration.
SBC can be configured to pass username set in Contact field. To do this you have to configure
registration contact username passthrough
This have to be set on adjacency that should not rewrite username when SIP REGISTER comes from
CUBE is marketing name of Cisco Unified Border Element, formerly known as Session Border Control. It’s meant to be implemented at the edge of the voice network as an interconnection between two or more VoIP networks providing security between them, CAC, billing etc. There are two models – CUBE known from IRS routers and CUBE-SP available on ASR 1000 and 7600 platform. Both of them works slightly different.
With CUBE-SP not all of the SIP methods are passed through SBC router by default. In example MESSAGE method is not which makes sending text messages between SIP phones impossible. SBC router responds with “405 Method now allowed” if it sees unsupported method in SIP message. But particular methods can be added to whitelist and therefor passed through SBC.
sbc CUBE
sbe
sip method-profile Pass-IM-Header
pass-body
method MESSAGE
action pass
adjacency sip Internal
method-profile inbound Pass-IM-Header
method-profile outbound Pass-IM-Header
adjacency sip Internet
method-profile inbound Pass-IM-Header
method-profile outbound Pass-IM-Header
In following example particular method is defined as accepted in method-profile, which is attached in both ways to adjacency. This way we can biuld complex policies allowing devices from one adjacency to pass some methods while blocking from others.