Multiple Tandem Samples

The following samples were prepared for Distributed Networking Associates by Sipro Lab Telecom Inc. For more information, visit their web site at

Traditional voice networks often route a call through several intermediate PBXes. This can cause problems for highly compressed voice mechanisms. Each "tandem" refers to one compression/decompression cycle. The solution to this problem is simply to design the packet voice network in a way that calls connect directly between the source and the destination. This usually means more defined PVCs, or maybe SVCs, for Frame Relay and ATM networks. IP usually provides a direct connection.

Reference Sample @ 44 khz

Reference Sample @ 8 khz

Reference Sample @ 64 kbps PCM

Algorithm 1 Tandem 3 Tandems 6 Tandems 10 Tandems
ITU G723.1 at 5.3 kbps (ACELP)
ITU G729A at 8 kbps (CS-ACELP)

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