Implementing and Operating Cisco Collaboration Core Technologies (CLCOR) — Question 366

SIP proxies have operations defined in RFC 3261 and supporting extensions. Though no IETF RFC completely defines how SBCs must function, SBCs evolved over the years. Which two operations demonstrate the high-level differences between SBCs and SIP proxies? (Choose two.)

Answer options

• A. SIP proxies are SDP-aware and can change the SDP bodies.
• B. SIP proxies add a Via header and optionally a Record-Route header, and the rest of the headers are left untouched.
• C. SBCs can modify headers such as To, From, Contact, and Call-ID. It can introduce new headers into the SIP message.
• D. Stateful proxies are context-aware and can terminate communication sessions by themselves.
• E. SBCs are capable of interworking completely different protocols to set up, modify, and tear down communication sessions. It includes SIP, H.323, and MGCP protocols.

Correct answer: C, E

Explanation

The correct answers, C and E, highlight that SBCs have the capability to modify critical headers and can handle various protocols, which distinguishes them from SIP proxies. Options A and B relate to SIP proxies' functionalities and do not address the unique capabilities of SBCs. Option D, while mentioning stateful proxies, does not differentiate SBCs from SIP proxies effectively.