How does a SIP line work?

A SIP line, or Session Initiation Protocol line, transmits voice calls over data lines and the Internet rather than traditional telephone lines.

Using ethernet or fiber-optic cabling, a SIP line can also accommodate other types of multimedia messaging, enabling organizations to adopt Unified Communications technology.

A SIP line supports Voice over the Internet Protocol (VoIP) telephony, converting calls to data for transmission over data lines.

A growing number of businesses are turning to SIP trunking over traditional PRI trunking when choosing solutions for enterprise voice services. But how does a SIP line work, exactly, and how does it deliver superior telephony options? Here is a short introduction to “How does a SIP line work?” that provides some detail.

A SIP line, or Session Initiation Protocol line, enables voice connections over the Internet and supports Voice over Internet Protocol (VoIP) telephony. A SIP line uses an existing Ethernet or fiber-optic line to transmit voice calls as data, along with other types of multimedia communications including videoconferencing, data transmissions, SMS messages and more.

How does a SIP line work vs. a PRI line?

A PRI line, or Primary Rate Interface line, provides a physical connection to the Public Switch Telephone Network (PSTN) while a SIP line provides a virtual connection. A single PRI line can only accommodate 23 simultaneous calls, while a SIP line is limited only by the amount of bandwidth for the data connection or by the number of call paths purchased from a SIP trunk provider.

How does a SIP line work to increase scalability?

A SIP line provides fast and easy scalability. To add or remove lines, IT administrators need only contact the SIP trunk provider to get virtual connections and individual phone numbers set up within in hours or days at the most. In contrast, adding PRI lines may require new infrastructure to be deployed and may take weeks to complete.

How does a SIP line work for call quality?

Because traffic on a SIP line competes for bandwidth with other applications and may be impacted by packet loss, jitter and network interference, call quality on a SIP line is thought to be inferior to a PRI line which uses dedicated, physical lines. Routing calls on a SIP line over dedicated fiber connections can help to improve call quality.

How does a SIP line work to reduce costs?

The cost of a SIP line may be 30 to 40% cheaper than a PRI line, though costs vary significantly depending on the size and complexity of implementation. SIP trunking requires no costly hardware to be installed or maintained, and thus th cost of making calls is much cheaper.

How does a SIP line work to provide redundancy?

If an Internet outage occurs, compromising available bandwidth for calls over a SIP line, voice traffic can be rerouted to a mobile phone or to a PRI line as a backup.