Chapter 1 Introduction | |
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In addition to the translation of individual bits, the signaling profiles can also be used to define the signaling bit patterns that indicate the idle and OOS states.
•CCS – The signaling information is transferred transparently to the host, which encapsulates the HDLC frame with the proper IP header and sends it to the main link. The following protocols are supported: ISDN, QSIG and SS7. HDLC data can be extracted from any set of timeslots and sent to a single destination. When operating with SS7 signaling, it is possible to control amount of the
Compression
The DSPs handle the voice traffic by compressing it according to G.723.1 (6.4 or
5.3kbps) and G.729 A (8 kbps), or digitizes it according to the G.711 requirements
Voice Activity Detection
Voice Activity Detection (VAD) uses digital signal processing techniques to distinguish between silence and speech on a voice connection. VAD reduces the bandwidth requirements of a voice connection by generating traffic only during periods of active voice conversation. With Comfort Noise Generation supported at the remote site, VAD significantly reduces bandwidth consumption without degrading voice quality. VAD achieves additional bandwidth savings when combined with voice compression techniques.
TDMoIP Multiplexing
Compressed voice payload is multiplexed by using the TDMoIP technique. The multiplexing is performed by the
TDMoIP AAL2 Voice AAL2 Voice
Header Header Packet Header Packet
Figure 1-6. TDMoIP Frame Structure
The size of TDMoIP frame is determined by the following parameters:
•Packetizing interval – Defining time interval allocated for the TDMoIP frame aggregation (10 to 90 msec).
•Maximum bytes per multiplexed frame – Specifying the maximum size of each frame (100 to 1461 bytes).
Functional Description |
