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From: mitel!spock!meier@uunet.uu.net (Rolf Meier)
Newsgroups: comp.dcom.telecom
Subject: Re: An Introduction to ISDN From the CERFnet News
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Date: 4 Oct 90 13:39:06 GMT
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X-Telecom-Digest: Volume 10, Issue 713, Message 4 of 11


In article <12978@accuvax.nwu.edu> goldstein@delni.enet.dec.com (Fred
R. Goldstein) writes:

>bits as it desires, preserving the audio content.  If you call between
>North America and Europe, the network MUST change speech and PCM audio
>because Europe and North America use different PCM standards!  They're
>mutually unintelligible, though both are 64 kbps PCM.  Similarly, the
>network MUST NOT change a clear channel (data).

Actually, if you decoded ulaw with an Alaw decoder, or vice versa, the
difference is practically inaudible compared to the use of the proper
decoder.  However, the conversion is made anyway, in order to meet the
quantization requirements.


Rolf Meier	Mitel Corporation