Ports Used for VoIP

By Susan Kerr

A computer becomes a communication device when specific ports are used for VoIP.
i computer image by Orlando Florin Rosu from Fotolia.com

Voice over Internet Protocol, or VoIP, enables computer users to make phone calls via the Internet without using a traditional telephone line. This is made possible by a variety of listening ports and hardware ports on a computer. Two primary types of listening ports are used: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). TCP ports are commonly used in VoIP transmissions, while UDP ports are used for administrative purposes such as resolving server conflicts and upgrading products. In additionally, VoIP phones require hardware ports for the use of accessories such as handsets and headsets.

Basic Ports

Port 5060 is used for both TCP and UDP transmissions. It is the gateway for VoIP communications including phone transmissions, streaming media, instant messaging, gaming and online conferencing. Port 5004 UDP is most often used for transmission of data packets within a computer network.

VoIP Provider Ports

Vonage and Skype, two well-known VoIP service providers, use a wide range of ports on a computer in the operation of their products. Ports 10000 through 20000, for example, are commonly used by Vonage for two-way communication through RTP (Real Time Protocol). Similarly, Skype uses ports 25000 through 40000 for this purpose. Other VoIP providers make use of these or other ports based based on their own product designs and requirements.

Special Purpose Ports

VoIP providers use a supplementary list of UDP ports for upgrading their products. The specific ports used vary from one service provider to the next. Check a provider's website for detailed information on the functions of these ports.

Hardware Ports

USB ports are required for the use of VoIP handsets, which often take the place of a conventional telephone. The audio port on a sound card may be used by headsets and external speakers to take advantage of speakerphone features. In addition, network ports are required whenever a modem, router or adapter is used for connecting to the Internet.