TDM Pseudowire

TDM pseudowires take advantage of the packet-switched (PSN) infrastructure to help both carriers and enterprises reduce network expenses without compromising functionality or services. The evolutionary TDM pseudowire approach maximizes investment protection by running all TDM traffic – irrespective of protocols or signaling – transparently over Ethernet/MPLS/IP networks.

 

TDM pseudowire is a technology developed (and standardized by the IETF, ITU-T and MEF) for carrying E1, T1, E3, or T3 circuits across the PSN, transparent to all protocols and signaling. It enables enterprises to run voice, video and legacy data over the PSN, thereby minimizing network maintenance and operating costs. TDM pseudowire enables service providers to migrate to packet-switched networks and continue to provide all their revenue-generating legacy voice and data services. TDM pseudowire also benefits data carriers by enabling them to offer lucrative leased line and private line services. This lets the carriers maximize revenues from their packet-switched infrastructure by selling voice services as well as data.

TDM pseudowire takes TDM data streams and converts them into packets for transmission over the PSN. The original traffic is reconstructed and the clocking is regenerated at the destination. Transparent connectivity over the PSN maintains all features and functionality of the legacy network. TDM pseudowire therefore provides seamless migration of a variety of legacy services to packet-switched networks, with full support for legacy equipment such as Class 4 and 5 switches, PBXs and TDM multiplexers. RAD has pioneered TDM pseudowires, introducing TDMoIP technology in 1999. Since then, two additional TDM pseudowire standards, named CESoPSN and SAToP, have been introduced via the IETF, ITU-T, MFA, and MEF. RAD's new IPmux product line builds on RAD's extensive TDM pseudowire experience and incorporates a newly designed TDM pseudowire ASIC processor that supports all TDM pseudowire standards. RAD's new TDM pseudowire gateways are able to function in TDMoIP, CESoPSN or SAToP modes.

RAD's TDM pseudowire offering includes the IPmux and Gmux TDM pseudowire gateways, Megaplex multiservice access multiplexers, and Vmux voice compression trunking gateways.

 

The IPmux family of TDM pseudowire gateways handles full E1/T1, fractional E1/T1 and E3/T3 streams, supporting ToS (DiffServ) on the IP layer and VLAN on the Ethernet layer.

 

The Gmux is a central office modular chassis for aggregating and terminating pseudowire traffic.

 

Megaplex multiplexers (see page 98), equipped with an internal TDMoIP main link module, work opposite the IPmux to function as full service TDM pseudowire gateways, and incorporate over 50 different I/O modules for voice, fax and data applications in ring, star and daisy-chain topologies.

 

RADview Service Center TDMoIP is an SNMP-based network management system designed to manage the TDM pseudowire gateways and provision leased line services in a quick, intuitive manner.

• Preserve investment in legacy devices

• Generate new service revenues

• Allow low cost deployment with quick installation

• Reduce operational costs

• Provide complete support for QoS features

Utility companies reduce expenses and simplify their networks by migrating legacy voice and SCADA applications over their more efficient Ethernet networks.

 

Incumbent carriers reduce infrastructure costs by utilizing their PSN cores for TDM transport.

 

Metropolitan carriers, cable operators and utilities/utelcos generate new revenue by delivering traditional leased line and private line services, such as E1/T1 and E3/T3, over IP/Ethernet/MPLS access networks.

 

Enterprises reduce network expenses with maximum investment protection by running all voice and TDM traffic over IP or Ethernet.

Carrier:

Using cable, HFC, radio, and fiber infrastructure to provide:

• Leased line services over IP, Ethernet or MPLS

• Private line over Metro Ethernet/TLS

• Cellular backhaul over IP/Ethernet/MPLS

• E1/T1 or E3/T3 over Fast Ethernet or Gigabit Ethernet metropolitan area networks

• SS7 transport over IP

 

Enterprise:

• E1/T1, voice, video, and TDM data over Ethernet

• Centralized voice services over Ethernet

• E1/T1 or E3/T3 over Fast Ethernet or Gigabit Ethernet

RAD’s TDM pseudowire technology enables carrier leased line services and enterprise clear channels to migrate to the packet-switched network and still benefit from all legacy and new services, streamlining operations over one network.

TDM pseudowire enables the packet-switched network to become an attractive alternative to currently used leased lines for backhauling cellular traffic between base stations (BTSs), base station controllers (BSCs) and mobile switching centers (MSCs). TDM pseudowire technology is used to provide transparent transport with minimal delay over fiber, cable, HFC, and fixed wireless links.

 

RAD's TDM pseudowire solution is suitable for both 2G and 3G cellular networks.

Unlike TDM and ATM networks, asynchronous PSNs do not transfer any timing information whatsoever. By using advanced clock recovery algorithms, TDM pseudowire gateways can recover the clock signal from the packets transported over the PSN, achieving the desired timing accuracy and complying with ITU-T G.823 and G.824 specifications despite the packet delay variation and packet loss inherent in the PSN.