codec functions

[sarahr202]

Hi everybody

http://www.en.voipforo.com/codec/codecs-g711-alaw.php

Based on the above link, codec performs quantization and codification.  My question is who performs sampling of analog signal if not  codec?

thanks and have a great day.

[Daniele Giordano · Accepted solution]

The DSP is the hardware processor used to accomplish these tasks.

http://en.wikipedia.org/wiki/Digital_signal_processing

Cisco uses PVDM (Packet Voice DSP Module):

http://www.cisco.com/en/US/prod/collateral/routers/ps5854/product_data_sheet0900aecd8016e845.html

Regards.