Cisco Cisco Expressway
Expressway Limitations and Unsupported Features when Using Mobile and Remote Access
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The Expressway cannot be used for Jabber Guest when it is used for MRA.
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The Expressway-C used for Mobile and Remote Access cannot also be used for Microsoft Interoperability.
Microsoft Interoperability requires a dedicated Expressway-C.
Microsoft Interoperability requires a dedicated Expressway-C.
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MRA is not supported in IPv6 only mode.
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Endpoint management capability (SNMP, SSH/HTTP access).
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Multi-domain and multi-customer support is limited as follows:
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Prior to X8.5, each Expressway deployment supported only one IM&P domain (even though IM and
Presence Service 10.0 or later supports Multiple Presence Domains).
Presence Service 10.0 or later supports Multiple Presence Domains).
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As of X8.5, you can create multiple deployments on the Expressway-C, but this feature is still limited to one
domain per deployment.
domain per deployment.
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As of X8.5.1, a deployment can have Multiple Presence Domains. This feature is in preview, and we
currently recommend that you do not exceed 50 domains.
currently recommend that you do not exceed 50 domains.
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NTLM authentication via the HTTP proxy.
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Maintenance mode; if the Expressway-C or the Expressway-E is placed into maintenance mode, any existing
calls passing through that Expressway will be dropped.
calls passing through that Expressway will be dropped.
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The Expressway-E must not have TURN services enabled.
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Deployments on Large VM servers are limited to 2500 proxied registrations to Unified CM (the same limit as
Small / Medium VM servers).
Small / Medium VM servers).
Protocol Summary
The table below lists the protocols and associated services used in the Unified Communications solution.
Protocol
Security
Service
SIP
TLS
Session establishment – Register, Invite etc.
HTTPS
TLS
Logon, provisioning/configuration, directory, visual voicemail
RTP
SRTP
Media - audio, video, content sharing
XMPP
TLS
Instant Messaging, Presence, Federation
Clustered Expressway Systems and Failover Considerations
You can configure a cluster of Expressway-Cs and a cluster of Expressway-Es to provide failover (redundancy)
support as well as improved scalability.
support as well as improved scalability.
and information about how to configure Jabber endpoints and DNS are contained in Configure
DNS for Cisco Jabber.
Note that when discovering Unified CM and IM&P servers on Expressway-C, you must do this on the primary peer.
Authorization Rate Control
The Expressway can limit the number of times that any user's credentials can be used, in a given configurable period,
to authorize the user for collaboration services. This feature is designed to thwart inadvertent or real denial of service
attacks, which can originate from multiple client devices authorizing the same user, or from clients that reauthorize
more often than necessary.
to authorize the user for collaboration services. This feature is designed to thwart inadvertent or real denial of service
attacks, which can originate from multiple client devices authorizing the same user, or from clients that reauthorize
more often than necessary.
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Mobile and Remote Access Through Cisco Expressway Deployment Guide
Additional Information