TCP/UDP Port Utilization

Like most equipment in your network, the 4600 Series IP Telephones use a variety of protocols (particularly TCP and UDP) to communicate with other equipment in that network - numerous different types of servers, routers, other telephones, etc. Part of this communication is identification of which TCP and/or UDP ports are to be used by each piece of equipment to support each protocol and task within the protocol. Depending on your network, you may need to know what ports (or ranges) are used in the 4600 Series IP Telephones’ operation so that you can appropriately administer your networking infrastructure. If so, you will find the following material useful.

In the diagrams that follow, Figure 2-1, Figure 2-2, Figure 2-3:

• The box on the left always represents the 4600 Series IP Telephone.
• Depending on the diagram, the boxes on the right refer to various pieces of network equipment with which the phone may (or will) communicate.
• Open-headed arrows (for example, ) represent the direction(s) of socket initialization.
• Closed-headed arrows (for example, ) represent the direction(s) of data transfer.
• The text associated with either end of the arrows identifies the port (one number) or ports (ranges given within brackets) supported by the 4600 Series IP Telephones for the specific situation, as well as any additional qualifications or clarifications. In many cases, the ports used are the ones called for by IETF or other standards bodies.
• Many of the explanations in the diagrams refer to system parameters or options settings (for example, IRSTAT or DIRSRVR) that are explained in Administering Options for the 4600 Series IP Telephones in Chapter 4, .