What is SIP and Tel URI?


The URI full form is Universal Resource Identifier. A resource could be anything like a document, a record, etc. This tutorial will describe two formats, SIP and Tel, for a URI for SIP protocol.

The SIP protocol has fields for addressing, To, From, etc. Each contains a URI. A URI is the basics of multimedia IP communication.

The SIP URI is specified in RFC 3261, and the Tell URI is in RFC 3966.

The SIP URI is like the name of a resource on a server. Like an email address, e.g., cspsprotocol@gmail.com. It is globally unique with a user name and domain name. If someone has to access resources, they first need to reach the server, then to the resource. 

For example, a mail sent to cspsprotocol@gmail.com first reaches the Gmail server and then goes to the account associated with cspsprotcol.

Sip URI Examplesip:+917876788@mnc345.mcc123.3gppnetwork.org

A TEL URI is a phone number. It can be for a fixed-line or mobile, etc.

Tel URI Example –  tel:+9885566666

What is SIP URI?

The sip URI means  Universal Resource Identifier. It is an address of an IP device over the SIP protocol. When you need to reach a VoIP phone, dial the sip URI. This may have many parameters. But here we will discuss a few basic ones.

The format is sip:user:password@host: port;

  • user – The name of the resource on the host.
  • password – A password associated with the hosting account. Generally, the use of a password is not recommended.
  • host – A domain name like www.iphoneservice.com or an IP address.
  • portUDP or TCP port number. If not specified, default port 5060 is used.

You can see that it’s different from how the GSM phone number works. The reason is that, essentially, VoIP was assumed to be another network. It will have all its network components and identities.

What is Tel URI?

You can imagine a TEL URI as a telephone number.

Example – tel:+91234555.

With it, a regular phone number can also be used for calling over the IP network. For international numbers, it is in E.164 format.