Avaya 1000 Manual page 6

Avaya Communication Server 1000 Port Utilization – Issue 4.04
Hybrid firewalls are dynamic systems, tracking each connection traversing all interfaces of the firewall and making sure they
are valid. In addition to looking at headers, the contents of the packet, up through the application layer, is examined. A
stateful inspection firewall also monitors the state of the connection and compiles the information in a state table. Stateful
inspection firewalls close off ports until the connection to the specific port is requested. This is an enhancement to security
1
against port scanning .
Firewall Policies
The goals of firewall policies are to monitor, authorize and log data flows and events. They also restrict access using IP
addresses, port numbers and application types and sub-types.
This paper is focused with identifying the port numbers used by Avaya products so effective firewall policies can be created
without disrupting business communications or opening unnecessary access into the network.
Knowing that the source column in the following matrices is the socket initiator is key in building some types of firewall
policies. Some firewalls can be configured to automatically create a return path through the firewall if the initiating source is
allowed through. This option removes the need to enter two firewall rules, one for each stream direction, but can also raise
security concerns.
Another feature of some firewalls is to create an umbrella policy that allows access for many independent data flows using a
common higher layer attribute. One example would be creating a policy to allow any H.323 data flows through the firewall.
This umbrella policy would allow H.225, H.245, H.248, RTCP and RTP streams to flow through the firewall without specifying
specific port ranges for each of these protocols.
Finally, many firewall policies can be avoided by placing endpoints and the servers that serve those endpoints in the same
firewall zone.
1
The act of systematically scanning a computer's ports. Since a port is a place where information goes into and out of a computer, port
scanning identifies open doors to a computer. Port scanning has legitimate uses in managing networks, but port scanning also can be
malicious in nature if someone is looking for a weakened access point to break into your computer.
Avaya – Proprietary.
6
Use pursuant to the terms of your signed agreement or Avaya policy.