Cisco Cisco TelePresence Video Communication Server Expressway

Appendix 2: IP Ports and Protocols

External firewalls between peers

It is unusual to have any sort of external firewall between cluster peers, but if there is, the IP protocols and ports that must
be open between each and every VCS peer in the cluster are listed below.

For cluster communications between VCS peers:

■

UDP port 500 (ISAKMP) is used for PKI (Public Key Infrastructure) key exchange

■

IP protocol 51 (IPSec AH) is used for database synchronization

For calls between VCS peers:

■

Standard SIP and H.323 signaling ports are used for calls

■

UDP port 1719 is used for bandwidth updates between VCS peers

Firewall rules on the peers

(This section does not apply to external firewalls)

If you are using the VCS's built-in Firewall rules feature, make sure that your rules do not prevent the following
connections:

Purpose

Protocol

Source

Port

Destination

Port

Cluster communication

TCP

Other peers

Ephemeral

This peer

4369-4380

Cluster recovery

UDP

Other peers

Ephemeral

This peer

4371

Table 1 Clustering connections

Cisco TelePresence Management Suite Provisioning Extension

For cluster communications between VCS peers and a Cisco TMS when running in Provisioning Extension mode:

■

VCS ephemeral port to port 443 on Cisco TMS (secure) or

■

VCS ephemeral port to port 80 on Cisco TMS

Note:

Ports 443 and 80 are the default values; they can be configured in the Cisco TMS IIS, and VCS if different

ports are required.

IPSec Communications

For IPSec between VCS cluster peers:

■

AES256 is used for encryption, SHA256 (4096 bit key length) is used for authentication; peers are identified by
their IP address and are authenticated using a pre-shared key

■

Main mode is used during the IKE exchange

■

diffie-hellman group ‘modp4096’ is used

MTU Size

The default MTU size on the VCS is 1500 bytes. Under normal conditions this has no effect on the cluster. However, if
there are network elements between the cluster peers (which is not recommended), you must ensure consistent

Cisco TelePresence VCS Cluster Creation and Maintenance Deployment Guide