Multiflex Trunk Dedicated Echo Cancellation Modules
Cisco® Multiflex Trunk Dedicated Echo Cancellation (MFT ECAN) Modules are dedicated resources for the Cisco Enhanced ITU-T G.168 ECAN feature, providing robust echo cancellation performance for demanding network environments. The modules are daughter cards that attach to Cisco Second-generation Multiflex Trunk Voice/WAN Interface Cards (MFT VWIC2 cards). The dedicated ECAN modules are available in 32- and 64-channel configurations, which match the requirements of the 1- and 2-port T1/E1 MFT VWIC2s, respectively. The 64-channel MFT ECAN Module is shown in Figure 1. Figure 2 shows the module attached to a 2 port T1/E1 MFT VWIC2.
The Cisco Enhanced ITU-T G.168 ECAN feature can be run either on the dedicated ECAN modules or the general voice resources that reside on the platform, network module, or advanced integration module. For example, Cisco 2800 Series and 3800 Series integrated services routers can use either the packet voice DSP modules (PVDM2s) mounted in the router chassis or the digital signal processor (DSP) resources on network modules to run the G.168 ECAN feature. When the G.168 ECAN feature is run on general voice resources, processing and memory constraints limit it to having at most 64-ms echo tail coverage. Although this is adequate in most network conditions, a larger echo tail coverage is sometimes required. In these situations, the dedicated ECAN modules, attached to the appropriate MFT VWIC2, can be used. The processing and memory resources of the dedicated ECAN modules enable the echo canceller to be configured with predefined settings and an extended 128-ms echo tail buffer, providing robust echo cancellation performance in these more demanding network environments.
