Avaya B5800 User Manual download pdf (Page 277)

Appendix A: Avaya port matrix for B5800

Branch Gateway and SIP

phones

This appendix provides example ingress and egress ports for B5800 Branch Gateway and SIP phones.

What are ports and how are they used?

TCP and UDP use ports (defined at http://www.iana.org/assignments/port-numbers) to route

traffic arriving at a particular IP device to the correct upper layer application. These ports are

logical descriptors (numbers) that help devices multiplex and de-multiplex information streams.

Consider your desktop PC. Multiple applications may be simultaneously receiving information.

In this example, email may use destination TCP port 25, a browser may use destination TCP

port 80 and a telnet session may use destination TCP port 23. These logical ports allow the

PC to de-multiplex a single incoming serial data packet stream into three mini-streams inside

the PC. Furthermore, each of the mini-streams is directed to the correct high-level application

because the port numbers identify which application each data mini-stream belongs. Every IP

device has incoming (Ingress) and outgoing (Egress) data streams.

Ports are used in TCP and UDP to name the ends of logical connections which carry data

flows. TCP and UDP streams have an IP address and port number for both source and

destination IP devices. The pairing of an IP address and a port number is called a socket

(discussed later). Therefore, each data stream is uniquely identified with two sockets. Source

and destination sockets must be known by the source before a data stream can be sent to the

destination. Some destination ports are “open” to receive data streams and are called

“listening” ports. Listening ports actively wait for a source (client) to make contact to a

destination (server) using a specific port that has a known protocol associate with that port

number. HTTPS, as an example, is assigned port number 443. When a destination IP device

is contacted by a source device using port 443, the destination uses the HTTPS protocol for

that data stream conversation.

Port type ranges

Port numbers are divided into the following three ranges:

Implementing B5800 Branch Gateway for a CS 1000 Configuration October 2012 277

1 2 ... 272 273 274 275 276 277 278 279 280 281 282 ... 323 324

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Avaya B5800 User Manual Page 277