Transcoding

 

Overview

Service providers have traditionally relied on TDM interconnections to move voice traffic on and off their networks, in part because of the high quality and reliable interconnections inherent in the technology. Recent advances in VoIP-based technology present a new lower-cost alternative that offers a quality and reliability that rivals TDM networks. VoIP networks have the added benefit of supporting advanced capabilities such as point to multi-point interconnection not available in TDM offerings.

This combination of the increased quality/reliability, advanced features, proliferation of VoIP-based networks, and the lower cost of VoIP is encouraging service providers to use VoIP peering solutions for network interconnection. with this transition to all-VoIP networks a new host of challenges arise. The use of the Public Internet brings up questions of security, quality, media interworking, and trust. Session border controllers and media gateways are the edge devices ideally suited to address these new challenges. Session border controllers provide the security for VoIP network interconnection through topology hiding and user authentication.

Session border controllers can also address the concerns of trust and signaling interworking. The last challenge on the edge of VoIP networks is Media Interworking. H.323 to SIP signaling interworking can be handled by the media gateway or by the session border controller. RTP layer transcoding is best handled by a hardware DSP-base media gateway.

 

IMG Solution

The rapid proliferation and growth of VoIP networks introduce new challenges for service providers. The replacement of TDM interconnection with VoIP peering introduces the requirement for Session Border Controllers for session management and Media Gateways for transcoding. The IMG solves current and future problems in next generation networks with its integrated transcoding. With its high density wireless and wireline codec support in a 1U form factor, the IMG is an excellent solution for the next generation service provider.

The IMG supports SIP, H.323, SS7, and ISDN giving true any-to-any voice network connectivity as well as simultaneous TDM and IP hairpins. The ability to support IP hairpins enables not only IP signaling translation, but media translation as well. As VoIP networks evolve and move away from the PSTN, wide-band codecs will gain popularity. The IMG, coupled with a Session Border Controller, is the ideal solution to bridge islands of VoIP traffic.

 

 

DG_Transcoding_Dialogic_Logos.png

 

 

 

Codecs/Maximum Session

 

Supported Codecs

Maximum Sessions IMG 1004

Maximum Sessions IMG 1004 (Profile 8)

Maximum Sessions IMG 1010

G.711 a-law

64

 

512

G.711 u-law

64

 

512

G.723.1 5.3kbps

64

 

512

G.723.1 6.3kbps

64

 

512

G.726-32/G.721

64

 

512

G.729 a/b/e

64

 

512

iLBC

42

 

336

GSM-AMR

42 (Profile 8 = 120)

 

336 (Profile 8 = 480)

GSM-FR

42

 

336

EVRC

42

 

336

Clear Channel Codec

64

 

512

 

 

Media / Transcoding Supported

All combinations in Table below can be run as long as the appropriate licensing and profile is loaded.

 

 

G.711

G.723.1

G.729 A/B/E

AMR

iLBC

G.726

GSM-FR

G.711

 

x

x

x

x

x

x

G.723.1

x

 

x

x

x

x

x

G.729 A/B/E

x

x

 

x

x

x

x

AMR

x

x

x

 

x

x

x

iLBC

x

x

x

x

 

x

x

G.726

x

x

x

x

x

 

x

GSM-FR

x

x

x

x

x

x