Media Paths And Interactive Connectivity Establishment; Phone Features Available For Mobile And Remote Access Through Expressway - Cisco 7800 Series Administration Manual

Media Paths and Interactive Connectivity Establishment

Scenario
Off-premises user logs in to the enterprise network
with Mobile and Remote Access Through
Expressway.
Media Paths and Interactive Connectivity Establishment
You can deploy Interactive Connectivity Establishment (ICE) to improve the reliability of Mobile and Remote
Access (MRA) calls that cross a firewall or Network Address Translation (NAT). ICE is an optional deployment
that uses Serial Tunneling and Traversal Using Relays around NAT services to select the best media path for
a call.
Secondary Turn Server and Turn Server Failover is not supported.
For more information about MRA and ICE, see System Configuration Guide for Cisco Unified Communications
Manager, Release 12.0(1) or later. You can also find additional information in the Internet Engineering Task
Force (IETF) Request for Comment documents:
• Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT
• Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal

Phone Features Available for Mobile and Remote Access Through Expressway

Mobile and Remote Access Through Expressway provides secure VPN-less access to collaboration services
for Cisco mobile and remote users. But to preserve network security, it limits access to some phone features.
The following list shows the phone features available with Mobile and Remote Access Through Expressway.
Cisco IP Phone 7800 Series Administration Guide for Cisco Unified Communications Manager
136
(STUN)(RFC 5766)
for Offer/Answer Protocols (RFC 5245)
Cisco IP Phone Administration
Actions
The phone detects that it is in off-premises mode, the
Mobile and Remote Access Through Expressway
Sign-In window appears, and the user connects to the
corporate network.
Users must have a valid service name, username, and
password to connect to the network.
Users must also reset the service mode to clear the
Alternate TFTP setting before they can access the
company network. This clears the Alternate TFTP
Server setting so the phone detects the off-premises
network.
If a phone is being deployed out of the box, users may
skip the reset Network Settings requirement.
If users have DHCP option 150 or option 66 enabled
on their network router, they may not be able to sign
in to the corporate network. Users should disable these
DHCP settings or configure their static IP address
directly.