Hub-Site Pseudowire and Voice Trunking Gateway

RAD’s Gmux-2000 is a modular, high capacity hub-site pseudowire and voice trunking gateway, extending TDM-based services over next generation packet-switched networks. As a pseudowire access gateway, the Gmux-2000 is widely used in cellular backhaul, PSTN access and PBX backhaul applications. It incorporates industry standards for Pseudowire Emulation Edge-to-Edge (PWE3), to transport up to 196 E1 or T1 links, or two channelized STM-1 or OC-3 circuits, over two Gigabit Ethernet network links.

As a carrier-grade voice trunking platform, the Gmux-2000 uses advanced compression algorithms to provide a 16:1 compression ratio, thus minimizing the bandwidth required for voice transmissions over packet networks and reducing cellular backhaul expenses.

• Reduces CapEx by enabling transition to cost-effective packet backbones using TDM pseudowire access

• Allows carriers to continue delivering legacy services while migrating to NG IP transport

• Reduces operational costs by aggregation and compression

• Ensures carrier grade voice quality

• Reduces cellular backhaul expenses by optimizing backhaul efficiency Enables carrier-class service continuity with fully redundant hardware

The Gmux-2000 is a cost-effective, modular pseudowire gateway that provides a high capacity, high-density solution for transporting multiple E1/T1 links over IP, Ethernet and MPLS-based networks.

Incorporating TDMoIP technology and complying with pseudowire emulation (PWE3) standards from the IETF, MFA Forum, and ITU-T, Gmux-2000 is available with a choice of STM-1/OC-3 or E1/T1 interfaces. For extending TDM/PDH services over packet-switched networks (PSNs), it can relay, concentrate and groom TDMoIP traffic using its STM-1/OC-3 channelized interfaces. Alternatively, Gmux-2000 can extend up to 196 individual E1 or T1 trunks over the PSN. Employing HDLCoPSN, the Gmux-2000 also supports HDLC-based legacy traffic transparently.

The Gmux-2000 works opposite RAD’s IPmux TDM pseudowire gateways or Megaplex integrated access multiplexers for cost-effective, carrier-class TDM pseudowire access. Together, they provide carriers with a migration path to packet-switched networks, while enabling them to continue delivering revenue-generating legacy services.

Additionally, the Gmux-2000 can be deployed as a carrier grade platform for large voice compression applications, condensing numerous E1/T1 streams or an STM-1/OC-3 trunk over E1/T1, SDH/SONET or GbE links. Interoperable with RAD’s Vmux-2100, Vmux-210 and Vmux-110 voice trunking gateways, it employs TDMoIP multiplexing and advanced compression algorithms, as well as voice activity detection and silence suppression, to achieve up to 16:1 bandwidth savings. Such an effective compression ratio enables the unit to transmit up to 112 E1/T1 links over as few as seven E1/T1s, or over a single GBE link, while maintaining carrier-grade voice quality. By optimizing signaling channels as SS7, PRI and others, the Gmux-2000 further reduces the overall required bandwidth.

Gmux-2000 comes in a 6U-high chassis, mountable in a 19" ETSI or ANSI rack. It employs a double StarLAN backplane, enabling the connection of two full Gigabit Ethernet trunks with any of the installed I/O modules. The I/O modules are interconnected by two telecom buses.

The Gmux-2000 chassis includes slots for the following modules:

• Up to two PSN network uplink modules or in-band management modules

• Two control modules

• Three AC/DC power supply modules

• Seven I/O modules (E1/T1 interface, STM-1/OC-3 interface and E1/T1 CE server types, or voice compression modules)

• Cooling fans module

Gigabit Ethernet network modules, each with a pair of redundant Gigabit Ethernet (GbE) uplinks, support Ethernet IEEE 802.3, 802.1Q (VLAN tagging) and 802.1p (priority/class of service).

E1/T1 TDMoIP modules provide conversion of E1/T1 traffic flows for transmission over packet network via the GbE network module. Several versions of the TDMoIP module are available:

• E1/T1 modules with 28 external E1 or T1 interfaces for applications where individual E1/T1 ports are needed to interface with TDM devices.

• E1/T1 circuit emulation (CE) server modules are used in conjunction with the STM-1/OC-3 interface modules. The E1/T1 CE server modules are used to extract 21 E1 or 28 T1 internal channels coming from the channelized STM-1/OC-3 interface module and convert them to TDM pseudowire traffic flows.

STM-1/OC-3 interface modules perform SDH/SONET multiplexing/demultiplexing of channelized STM-1/OC-3 trunks into separate, internal E1/T1 circuits (for TDMoIP encapsulation by CE server modules or for processing by the voice compression modules). Each STM-1/OC-3 interface module provides a pair of ITU-T G.703 coax or G.957, G.958 fiber optic links, supporting 1+1 redundancy according to ITU-T G.783.

Voice compression modules – the Gmux-2000 supports up to seven voice compression modules, each capable of handling 12 or 16 incoming E1/T1s. The compressed voice is transmitted over the E1/T1 main link ports on the module itself, or through the internal bus to the GbE network module. These modules function as server modules, meaning they can receive the voice directly from the PBX/MSC (via a direct Telco cable), or they can process voice coming in from an STM-1 module. In addition, they can operate in point-to-multipoint topologies. This brings the maximum capacity of the Gmux-2000, when functioning as a central site voice trunking gateway, to 3,472 voice channels.

Control modules provide the SNMP and user interfaces, as well as database storage, enabling configuration and control of the entire Gmux-2000 system. These modules are equipped with an RS-232 port, as well as a 10/100BaseT port for out-of-band management. Each control module provides redundant interfaces for connecting external G.812 station clocks and for alarm inputs/outputs.

Power supplies are hot-swappable plug-in modules. Up to three AC/DC power supply modules can be installed for load-sharing and redundancy. Two modules are required to drive a fully equipped Gmux-2000 system.

The Gmux-2000 is part of an overall solution for transferring TDM bundles over IP, MPLS or Ethernet networks end-to-end, from the CPE to the point-of-presence (POP) or to the central office (CO). Thus, management of the entire system should ideally be performed using a single management application. The RADview Service Center TDMoIP is such unified management application, combining a user-friendly interface with both element and network management level capabilities.