What are two functions of Cisco Expressway in the Collaboration Edge? (Choose two.)

The Cisco Expressway solution, composed of Expressway-C (Core) and Expressway-E (Edge), forms the Collaboration Edge. A primary function of this pair is protocol interworking, enabling seamless communication by translating between H.323 and SIP signaling protocols for voice and video calls, which is essential for business-to-business (B2B) collaboration. Additionally, the architectural design places the Expressway-E server in the demilitarized zone (DMZ). This positioning creates a secure perimeter, acting as a traversal point that separates the trusted internal enterprise network from the untrusted public internet, securely tunneling collaboration traffic to the internal Expressway-C.

A. Expressway secures both Mobile and Remote Access (MRA) and business-to-business communications through its encrypted traversal link. The statement that it does not encrypt B2B is false.
B. PSTN connectivity using T1/E1 trunks is a function of a voice gateway or Cisco Unified Border Element (CUBE), not the Cisco Expressway series.
D. Expressway provides VPN-less access for collaboration endpoints via its MRA feature. Cisco AnyConnect is a separate VPN client solution and is not a function of Expressway.

1. Cisco Expressway Administrator Guide (X14.2), "About Cisco Expressway Series," page 11. This section states, "The key features of the Cisco Expressway series include: ... Interoperability between H.323 and SIP devices, and between IPv4 and IPv6 networks." This directly supports option C.

2. Cisco Expressway IP Port Usage for Firewall Traversal Deployment Guide (X14.2), "Introduction to the Cisco Expressway Series," page 7. This document illustrates the architecture, showing "The Expressway-E is designed to be located in a DMZ" and "The Expressway-C is designed to be located in the internal network." This confirms the perimeter network function described in option E.

3. Mobile and Remote Access Through Cisco Expressway Deployment Guide (X14.2), "Introduction," page 9. This guide explicitly states that MRA provides connectivity for remote endpoints "without requiring a VPN connection," which refutes the claim in option D.

4. Cisco Collaboration System 12.x Solution Reference Network Designs (SRND), "Collaboration Edge," page 8-4. The SRND states, "The Expressway solution does not provide PSTN access. PSTN access is provided by a Cisco Unified Border Element (CUBE) or a local gateway." This directly refutes option B.