Cisco Cisco TelePresence Video Communication Server Expressway

Notes:

■

Ensure that the

cisco-uds

SRV records are NOT resolvable outside of the internal network, otherwise the

Jabber client will not start mobile and remote access negotiation via the VCS Expressway.

■

You must create internal DNS records, for both forward and reverse lookups, for all Unified Communications
nodes used with Mobile and Remote Access. This allows VCS Control to find the nodes when IP addresses or
hostnames are used instead of FQDNs.

DNS SRV Configuration for Legacy Video Conferencing Deployments

The format of DNS SRV queries for sip (RFC 3263) and H.323 used by VCS are:

■

_sips._tcp.<fully.qualified.domain>

■

_sip._tcp.<fully.qualified.domain>

■

_sip._udp.<fully.qualified.domain> - not recommended for video calls, only use for audio-only calls

■

_h323ls._udp.<fully.qualified.domain> - for UDP location (RAS) signaling, such as LRQ

■

_h323cs._tcp.<fully.qualified.domain> - for H.323 call signaling

The format of DNS SRV queries for sip (RFC 3263) and H.323 typically used by an endpoint are:

■

_sips._tcp.<fully.qualified.domain>

■

_sip._tcp.<fully.qualified.domain>

■

_sip._udp.<fully.qualified.domain> - not recommended for video calls, only use for audio-only calls

■

_h323ls._udp.<fully.qualified.domain> - for UDP location (RAS) signaling, such as LRQ

■

_h323cs._tcp.<fully.qualified.domain> - for H.323 call signaling

■

_h323rs._udp.<fully.qualified.domain> - for H.323 registrations

Note that UDP is not a recommended transport medium for video signaling; SIP messaging for video system is too
large to be reliably carried on datagram-based (rather than stream-based) transports.

The VCS Cluster name (configured on the System > Clustering page) should be the <fully.qualified.domain>
specified in the DNS SRV records that point to the VCS cluster.

Example

DNS SRV records for 2 peers of a VCS-E cluster for example.com

where:

■

FQDN of VCS Expressway peer 1: vcse1.example.com

■

FQDN of VCS Expressway peer 2: vcse2.example.com

■

FQDN of VCS Expressway cluster: example.com

_sips._tcp.example.com. 86400 IN SRV 1 1 5061 vcse1.example.com.

_sips._tcp.example.com. 86400 IN SRV 1 1 5061 vcse2.example.com.

_sip._tcp.example.com. 86400 IN SRV 1 1 5060 vcse1.example.com.

_sip._tcp.example.com. 86400 IN SRV 1 1 5060 vcse2.example.com.

_h323ls._udp.example.com. 86400 IN SRV 1 1 1719 vcse1.example.com.

_h323ls._udp.example.com. 86400 IN SRV 1 1 1719 vcse2.example.com.

_h323cs._tcp.example.com. 86400 IN SRV 1 1 1720 vcse1.example.com.

_h323cs._tcp.example.com. 86400 IN SRV 1 1 1720 vcse2.example.com.

_h323rs._udp.example.com. 86400 IN SRV 1 1 1719 vcse1.example.com.

_h323rs._udp.example.com. 86400 IN SRV 1 1 1719 vcse2.example.com.

Cisco TelePresence VCS Cluster Creation and Maintenance Deployment Guide

Appendix 3: Cluster Name and DNS SRV Records