PRI to SIP Gateways

What is a VoIP Gateway?

A VoIP Gateway allows you to convert between a legacy telephony connection, such as E1/T1/PRI and a modern VoIP connection using SIP. This is known as "digital gateway" because the voice media is converted between a digital TDM connection and a VoIP connection. The conversion can go from SIP to TDM, TDM to SIP or even SIP to SIP for the purposes of failover or transcoding. In a TDM-to-SIP deployment, the gateway significantly reduces operating costs by connecting a legacy business phone system with dynamic SIP trunking services. SIP-to-TDM deployments use the VoIP gateway to connect a modern SIP communications system with T1/E1/PRI service from legacy carriers. There are many applications for VoIP media gateways.

Public Switched Telephone Network T1/E1/PRI to VoIP

A VoIP gateway can connect a modern VoIP-only system, for example a virtualized IP PBX, to a PSTN PRI trunk.

VoIP Provider to Legacy PBX

An IP Media Gateway can be used to upgrade a legacy business phone system allowing it to use a SIP trunk out to an ITSP. SIP Trunks are more cost-effective than expensive legacy T1 lines.

Legacy PBX to IP PBX Migration

The VoIP gateway also acts as a bridge connecting a legacy PBX via a PRI interface and an IP PBX via a SIP connection to support a migration initiative.

Terms / Acronyms:

• VoIP - Voice over IP
• SIP - Session Initiation Protocol
• IP - Internet Protocol
• TDM - Time Division Multiplexing
• PRI - Primary Rate Interface
• ISDN - Integrated Services Digital Network
• PSTN - Public Switched Telephone Network
• ITSP - Internet Telephony Service Provider

A VoIP gateway may also be referred to by any of the following:

• IP Media gateway
• SIP gateway
• Voice gateway
• TDM gateway
• PSTN gateway
• PRI gateway
• ISDN gateway
• Digital Telephony gateway

The terms VoIP Gateway and IP Media Gateway are the most common names for this type of device.

What Makes Digium Gateways So Reliable?

Digium IP Media Gateways are industrial grade high-performance appliances. The combination of a state of the art embedded hardware architecture and a software architecture built upon the Asterisk communications engine gives the G-Series its rock-solid reliability.

Digium is the global leader in the manufacture of telephony interfaces cards. Companies have come to trust Digium quality which has been ISO 9000 certified since 2008. When we designed our VoIP Gateway appliances we built upon our years of experience engineering high quality PSTN interfaces. We chose an embedded design so there are no moving parts. This means Digium Gateways run cool and last long.

Asterisk is the world's leading open source communications platform. Deployed in over 170 countries around the world from small businesses to Fortune 500 companies, Asterisk is the engine to use when your business needs to rely on its communications. By leveraging the power of Asterisk, Digium is able to engineer gateways with amazing performance. And, because Asterisk is open source, Digium gateways provide high quality media conversion at an extremely compelling price-point, making Digium Gateways the best value on the VoIP Gateway market.

Digium G-Series Appliances