Voice Compression
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VMUX-2100

Features

• Supports bandwidth efficient transmission of up to 16 E1, T1 or PRI voice trunks over a single IP or E1/T1 link.

• Simultaneous transmission over IP and TDM networks

• Unique TDMoIP Multiplexing, together with various voice compression algorithms, provides up to 16:1 effective bandwidth utilization

• Single Ethernet and redundant E1/T1 uplink ports available

• Bandwidth is dynamically allocated according to Voice Activity Detection and silence suppression

• G.168 Echo Cancellation of up to 16 msec per channel

• Group III Fax relay support, at rates of 2.4 to 14.4 kbps

• Transparent modem support for all common rates and standards

• QoS support:

  • Labeling IP level priority (ToS)

  • VLAN tagging and priority labeling according to IEEE 802.1p&q

• Supports HDLC Channel Compression

• DTMF/MFR2/MFC signal detection, generation and relay

• Signaling supported:

  • Transparent CAS signaling, including R2 and E&M

  • Transparent CCS signaling, including ISDN, QSIG and SS7

• Management via user terminal, secured SNMP and Telnet

• Enhanced local and remote diagnostics tools

• Hot swappable voice modules

• Optional dual hot-swappable power supply modules for load sharing and redundancy

• Compact 1U-high platform, compatible with 19" racks

Description

• Vmux-2100 is a modular Voice Trunking Gateway that compresses and transports up to 16 E1 or T1 voice trunks over E1, T1 or IP links. Vmux-2100 employs G.723.1, G.729 Annex A and G.711 compression algorithms, together with RAD's unique TDMoIP Multiplexing, to transmit up to 480/384 voice channels, including transparent CAS and CCS signaling, over a single E1/T1 or IP link.
  
   

• Voice Activity Detection and silence suppression techniques are used by Vmux-2100, so that bandwidth is only allocated when it is required, thus conserving bandwidth. The gateway detects, generates and relays DTMF/MFR2/MFC signaling.
  
   

• Vmux-2100 supports relay of Group III fax, as well as all common modem rates and standards. Modem transmissions are handled as voice band data.
  
   

• Vmux-2100, only 1U-high, is a compact modular unit, that can be installed in 19" racks. The unit consists of up to four Voice Compression modules, a single Main Link module, and up to two power supply modules. All modules are plug-in and field-replaceable. Power supply and Voice Compression modules are hot-swappable.
  
   

• Vmux-2100 is unique in that it is a single device that can provide compressed voice transmission over both TDM and IP networks, and easily switch between them whenever this may be advantageous or necessary. Switching transmission between TDM and IP links does not require additional investments in equipment and only minimal configuration changes.

MAIN LINK MODULE

• The Main Link module features a single 10/100BaseT UTP or fiber optic Ethernet port with optional Auto-Negotiation support. The Ethernet port operates at 10/100 Mbps speeds, half and full duplex. The Ethernet interface is compliant with the IEEE 802.3 standard. It supports full Auto-Negotiation according to 802.3x flow control for full duplex, and backpressure option for half duplex.
  
   

• In addition to the standard Ethernet port, the Main Link module can also be ordered with a redundant pair of E1 or T1 ports with RJ-45 connectors.
  
   

• E1/T1 link redundancy is controlled by the main board host, based on physical alarm reports, providing automatic switching between the redundant E1/T1 links in case of a link failure.
  
   

• Ethernet performance monitoring and statistics are available for frames received and sent to the IP network, collisions, deferred transmission and carrier sense errors (RFC 1643).

VOICE COMPRESSION MODULES

• Each Vmux-2100 Voice Compression module includes 2 or 4 E1/T1 ports. The timeslots received from the PBX E1/T1 trunks are compressed by the modules using standard G.711, G.723.1, or G.729.A algorithms. The compressed payload bytes are then encapsulated into a TDMoIP frame that runs over IP. The size and packetizing interval are user-configurable. The Ethernet frames are forwarded to the Ethernet switch, which sends them to one of the main links: 10/100BaseT or E1/T1.
  
   

• Timeslots are grouped together into bundles. A different destination IP address can be configured for each bundle to support any-to-any connectivity (see Figure 1).
  
   

• Vmux-2100 utilizes the Voice Activity Detection mechanism that prevents sending packets when no voice activity is detected, to increase bandwidth utilization and thus support a higher number of voice channels over TDM links
  than is possible using conventional voice compression methods alone. By TDMoIP Multiplexing and grouping the timeslots of G.723.1 compressed voice together into bundles with a common IP address, actual link bandwidth used per channel can be reduced to as low as 4 kbps (a reduction of 16:1). This enables a single Vmux-2100 unit, fully equipped with four 4-port Voice Compression modules, to compress and transmit up 16 E1 or T1 trunks (480/384 voice channels) over a single 2 Mbps E1 or 1.5 Mbps T1 link (see Figure 3).
  
   

• CAS and CCS signaling are transparently transmitted
  end-to-end (see Figure 2). Vmux-2100 transmits HDLC-based CCS signaling protocols such as SS7, ISDN and QSIG as HDLC over IP. HDLC frames are removed, and any signal payload is sent in an IP packet. For ISDN and QSIG protocols, this results in significant bandwidth savings.

QOS SUPPORT

• Vmux-2100's IP port complies with all relevant Ethernet LAN standards, such as IEEE 802.3 and 802.3u. It provides reliable, high quality of service (QoS), by optional VLAN tagging and priority labeling according to IEEE 802.1p&q.
  
   

• The user can configure the ToS (Type of Service) of the outgoing IP frames. This allows an en-route Layer-3 router or switch, which
  supports ToS (or Diffserv), to give higher priority to Vmux-2100 IP traffic for delay-sensitive applications.
  
   

• Assigned, IANA-registered UDP socket number for TDMoIP simplifies flow classification through switches and routers.

MANAGEMENT

• All operating parameters of the Vmux-2100 are configured using a simple, menu-based software. For upgrades or backup, software upload and download can be performed via TFTP.
  
   

• Vmux-2100 can be configured and monitored via a local ASCII terminal, Telnet, or via RADview, RAD's Network Management system. Vmux-2100 has a DB-9 Control port for the local terminal connection used for monitoring and control. For off-site management, a terminal can also be connected via a modem extension to the Control port using the optional CBL-VMUX-MM-MODEM cable.
  
   

• Since Vmux-2100's internal control unit has its own IP address, the Ethernet port can also be conveniently utilized as a connection to management systems running over Ethernet networks. Management connected to the Ethernet port can even serve a remote unit that is connected via an E1/T1 link, by placing the management information in a dedicated timeslot of the TDM link (in-band management). See Figure 4.
  
   

• For system security, Vmux-2100 provides four different levels for users: Monitor, Technician, Operator and Administrator. Up to 20 different usernames with passwords can be defined.