AudioCodes Cable Media (Trunking) Gateways Play an Important Role in PacketCable Architecture

	by Yossi Kurtzman, Director, Product Marketing, Systems Group

AudioCodes offers Cable Access Network vendors, MSOs, NEPs and cable integrators the Mediant™ 5000/8000 Media Gateways. Serving as a MG (Media Gateway), the Mediant 5000 received PacketCable™ Qualification status from CableLabs®, ensuring our readiness for interoperability with other PacketCable compliant network elements. Israel-based HOT Telecom is the first service provider that has started a full scale deployment with the Mediant 8000 as an MG in its network. HOT Telecom is a superbrand of three Israeli cable companies with approximately 1.3 million subscribers in the areas of multi-channel TV, Internet and data communication and transmission.

The following is an overview of PacketCable network architecture and the role AudioCodes' Mediant MG family plays in this network:

PacketCable Architecture
At a very high level, PacketCable 1.0 architecture contains three networks: the "DOCSIS HFC Access Network", the "Managed IP Network" and the PSTN. The Cable Modem Termination System (CMTS) provides connectivity between the "DOCSIS HFC Access Network" and the "Managed IP Network". Both the Signaling Gateway (SG) and the Media Gateway (MG) provide connectivity between the "Managed IP Network" and the PSTN. The reference architecture for PacketCable 1.0 is shown in Figure 1.

Figure 1

The managed IP network serves several functions. First, it provides interconnection between basic functional PacketCable components responsible for the establishment of signaling, media, provisioning and quality of service. In addition, the managed IP network provides long-haul IP connectivity between other managed IP and DOCSIS HFC networks. The Managed IP network includes the following functional components: Call Management Server (CMS), Announcement Server (ANS), several Operational Support System (OSS) back-office servers, Signaling Gateway (SG), Media Gateway (MG) and Media Gateway Controller (MGC).

Mediant 5000/8000 Function (MG) — TGCP Control

The Mediant 5000/8000 provides the MG functions. It provides bearer connectivity between the PSTN and the PacketCable IP network. Each bearer is represented as an endpoint and the MGC instructs the Mediant 5000/8000 to set up and control media connections to other endpoints on the PacketCable network. The MGC also instructs the Mediant 5000/8000 to detect and generate events and signals relevant to the call state known to the MGC.

The MGC uses the TGCP (Trunking Gateway Control Protocol) for the above media control functions and the media itself is conveyed in RTP streams. The Mediant 5000/8000 also supports TGCP security (IKE/IPsec) and media security (AES encryption /HMAC Authentication).

Key Features