Cisco Cisco Expressway Maintenance Manual
example, some calls may use Duo Video, or other calls might be audio only).
n
system supports up to 6000 relays, spread evenly across 6 ports where each port is limited to
handling 1000 relays. This limit is not strictly enforced, so we recommend adding an SRV record for each
port to enable round robin.
port to enable round robin.
n
Clustered Expressways: if the requested TURN server's relays are fully allocated the server will respond
to the requesting client with the details of an alternative server in the cluster (the TURN server currently
with the most available resources).
to the requesting client with the details of an alternative server in the cluster (the TURN server currently
with the most available resources).
n
The Expressway's TURN services are supported over single and dual network interfaces (via the
Advanced Networking option). For dual network interfaces, the TURN server listens on both interfaces but
relays are allocated only on the Expressway's externally facing LAN interface.
Advanced Networking option). For dual network interfaces, the TURN server listens on both interfaces but
relays are allocated only on the Expressway's externally facing LAN interface.
n
Microsoft ICE (which is not standards-based) is not supported by the Expressway-E's TURN server; to
enable communications between the Expressway and Microsoft Lync clients that are registered through a
Microsoft Edge Server you need to use the
enable communications between the Expressway and Microsoft Lync clients that are registered through a
Microsoft Edge Server you need to use the
.
n
The TURN server does not support bandwidth requests. Traversal zone bandwidth limits do not apply.
n
The Expressway-E TURN server supports TURN media over TCP and UDP. Configuration of the
supported protocols is available only through the CLI command xConfiguration Traversal
Server TURN ProtocolMode
supported protocols is available only through the CLI command xConfiguration Traversal
Server TURN ProtocolMode
.
n
The Expressway-E TURN server supports UDP relays over TCP; it does not currently support TCP relays.
Configuring TURN services
Relay option key (this controls the number of TURN relays that can be simultaneously allocated by the
TURN server).
TURN server).
The
TURN
page (
Configuration > Traversal > TURN
) is used to configure the Expressway-E's TURN
settings.
The configurable options are:
Field
Description
Usage tips
TURN
services
services
Determines whether the Expressway offers TURN
services to traversal clients.
services to traversal clients.
Cisco Expressway Administrator Guide (X8.5)
Page 56 of 394
Firewall traversal
About ICE and TURN services