Voice Trunking Gateway

RAD’s Vmux-2120 voice compression system and 3G media gateway for carrier-grade voice trunking provides compressed voice transmission over both TDM and IP networks. It compresses up to 16 E1/T1 circuits over redundant E1/T1 or Ethernet access links, with backup between the TDM and IP connections. In addition to its TDMoIP multiplexing and powerful voice compression capabilities, the Vmux-2120 universal voice trunking gateway supplies 3G media gateway services and is interoperable with NG-MSCs and softswitches.

 

The Vmux-2120 compressed voice system is an ideal solution for cellular operators and service providers looking to replace expensive leased lines with cost-effective packet transport.

• Provides a seamless migration path from TDM to IP without affecting voice quality or existing user equipment

• Enables leased line replacement between MSCs or between MSCs and PSTN

• Allows mobile operators to leverage the existing 2G backbone segments while introducing 3G NG-MSC

• Helps international/long distance telecom providers and call centers to reduce the number of leased lines

• Supports disaster recovery solution providers in saving on expensive satellite bandwidth

Voice Compression over TDM and IP Transport

The Vmux-2120 voice compression system and universal voice trunking gateway employs G.723.1, G.729 Annex A, AMR and G.711 compression algorithms, together with RAD’s unique TDMoIP multiplexing, to transmit up to 496/384 voice channels, including transparent CAS and CCS, over a single E1, T1 or IP link. Compressed voice can be transmitted over both TDM and IP networks by a single Vmux-2120 device. This unique capability enables the Vmux-2120 to easily switch between networks when necessary, without requiring additional equipment. Voice activity detection (VAD) and silence suppression allow Vmux-2120 units to dynamically allocate bandwidth for voice traffic as needed, resulting in highly efficient bandwidth utilization over fewer links and freeing up line capacity for data transport.

 

In addition, the Vmux-2120 supports transparent delivery of voice band data, optimized transmission of multiple HDLC and SS7 channels, and transparent n x 64 streams. All CCS protocols, such as SS7, ISDN and QSIG are supported. The device’s full signaling transparency ensures seamless integration that does not involve retraining costs or loss of functionality.

By combining voice/fax capabilities with Ethernet data traffic over a single delivery network, operators can save significantly on the costs of running their networks. The Vmux-2120’s TDMoIP capabilities enable higher bandwidth savings (16:1) than any standard VoIP solution, while providing an effective migration path to IP. With Super-Tandem support (also known as TFO – Transcoder-Free Operation), it ensures a single compression cycle end-to-end for calls connected via multiple Vmux units, thereby avoiding voice degradation and delay. In addition, the Vmux-2120 offers improved resiliency to packet loss and supports bandwidth control mechanisms for congestion avoidance.

Network operators that already use the Vmux-2120 for voice trunking applications in 2G mobile networks can easily meet the requirements of 3G networks with a simple software upgrade. Featuring a processing capacity of 4, 8, 12 or 16 E1/T1 links, the Vmux-2120 supports standard 3G protocols, such as MEGACO/ITU-T Rec. H.248 and SIGTRAN.

The Vmux-2120 features flexible management capabilities, including local management via an ASCII terminal (RS-232). In addition, remote management can be performed either inband or out-of-band, using one of the network ports or the dedicated management port, while maintaining separation between management and user traffic via the use of VLANs. Advanced FCAPS (Fault, Configuration, Accounting, Performance, Security), service provisioning and diagnostic tools are provided by RADview-SC/Vmux, RAD’s network management system, via an SNMP-based GUI.

The compact, 1U-high Vmux-2120 can be installed in 19-inch racks and features the smallest footprint compared to any TDM voice compression or VoIP product of equivalent capacity. In addition to TDM and Ethernet port redundancy, as well as redundant hot-swappable power supplies, the system supports hot-standby, hot-swappable card redundancy and allows hitless software upgrades.