SIP Trunking-Definitions

SIP is a networking term and stands for Session Initiation Protocol. A SIP Trunk is the way that a phone company delivers telephony services over data link.

Sip trunk connects business PBX (private branch exchange) to PSTN (public switched telephone network).

The actual trunk hardware carries the phone calls from the business site to the PSTN‚ giving the business their phone service.

The advantage of using SIP trunk is that it replaces number of pairs of physical cables  from telephone service provider over a data network.

This data network can consist of a dedicated line‚ a shared connection with a data service or even by using Internet for connectivity.

SIP Trunking services offers very practical features which include local and long distance calls ‚ call recording‚ media conferencing‚ toll free number calling‚ voice messaging‚ and IP-PBX hosting features‚ among a few more others.

What are the advantages of SIP Trunking over Analog Circuits?

SIP Trunks are cheaper than analog circuits while maintaining the same service that businesses expect from line quality.

In addition‚ long distance termination charges associated with SIP Trunks are much cheaper than traditional analog or TDM rates. Unlimited number of voice sessions can be carried over a SIP trunk (only limitation is bandwidth).

What are the Advantages of SIP Trunks over PRI?

Are you wasting money on your PRI? SIP Trunking is the next-generation platform that gives businesses the ability to scale their voice solution gradually to meet your individual business needs.

Your administration of your network is reduced by reducing providers and you save money by right sizing your bloated telecom budget.

SIP Trunks realize its savings over PRI through the reduced costs of purchasing only lines that are needed. And can share these lines across multiple sites‚ since PRI are 30-channel minimum and it often forces locations to buy more capacity than is needed.

As a general rule most businesses only need to reserve phone lines for 1/3 of your corporate employees. If you have 99 employees you only need to support 3′ shared phone lines.

Since a PRI is only delivered in sets of 30 channels‚ it means that the business will require 3′ lines and must buy 2 PRI (60 channels). Waste of money and phone lines.

SIP Trunks reduce over provisioning and waste of money during seasonal call volume. Trunks can be provisioned as necessary. You can grow with SIP Trunks‚ PRI require purchasing 30 lines SIP Trunks can be bought one at a time with remote turn-up.

A single vendor can provide all SIP trunks whilst you May have to manage multiple vendors to deploy POTS‚ PRI‚ in multiple markets. Accounts must be set up for multiple accounts for voice and data.

You have to have multiple circuits for voice data; with SIP the IP connection can be leveraged to converge voice and data.

Most businesses May have ~30% to 40% excess capacity on their current internet access. This bandwidth can be used to run some or all of your voice traffic with SIP Trunking.

The Bandwidth can be allocated dynamically between the voice and data with SIP Trunks‚ helping to avoid waste.

Do I need more Internet Connectivity when I buy SIP Trunks?

Since SIP Trunks are virtual circuits delivered over an Internet Access line. A business May have to consider buying more internet connectivity based on the number of SIP Trunks purchased.

It is important to know that when a SIP trunk is not being used‚ the bandwidth allocated to a SIP Trunk is freed up for use on less intensive applications‚ such as email and general web use. This dynamic bandwidth allocation is a feature of SIP Trunks.

Author is a telecom professional having vast knowledge and experience in converged network. For more converged network articles and information.

Please visit  “” and “

Top Rated Popular products: