Digital trunking gateway: ETG3000 series
ETG3000 series is a kind of digital trunking gateway based on embedded operating system. It supports standard SIP/H.323 protocol, with large-capacity carrier class telephone trunking gateway functions. Currently it supports two to eight E1/T1 interfaces and can realize intercommunication with mainstream manufacturers softswitch system, and interwork  with carrier's local Telephone exchange by PRI/SS7 interface.

• Protocol interface: standard SIP 1.0/2.0; H.323 V4 protocol PRI network
      side/user side SS7 TUP/ISUP protocol.
• Voice codec: standard G.711A/U,G.723,G.729AB.iLibc, supporting voice 
      quality guarante eing technologies such as VAD (Voice activity detection),
      CNG (Comfort Noise Generation),JitterBuffer and EC,  reducing time delay 
      and distortion.
• Hardware interface: two FE0/FE1 interfaces connecting to L3/L2 exchange
      of IP metropo litan area network (MAN), also called business interface or
      network management interface several E1 interfaces (support two to eight
      E1/T1 interfaces).
• High compatibility: capable of intercommunicating with different manufacturers
      softswitch system.
• Carrier-class access equipment: multi-route control, interval control, call
      forbid,call number  limit, number replacement.
• Security guarantee: as an embedded system, it is reliable and stable, won't be
      disturbed by any virus, and provides a good certification mechanism to protect
      user's interests.
• Hot standby: double power supplies ensure the system runs normally & reliably