From owner-freebsd-isdn Wed Oct 17 11:56:23 2001 Delivered-To: freebsd-isdn@freebsd.org Received: from azeotrope.org (yerfable.azeotrope.org [216.30.51.220]) by hub.freebsd.org (Postfix) with ESMTP id 800C737B40A for ; Wed, 17 Oct 2001 11:56:19 -0700 (PDT) Received: from localhost (localhost [[UNIX: localhost]]) by azeotrope.org (8.11.6/8.11.6) with ESMTP id f9HIuIC15470 for ; Wed, 17 Oct 2001 13:56:18 -0500 (CDT) Date: Wed, 17 Oct 2001 13:56:17 -0500 (CDT) From: Dave Huang To: Subject: Re: NetJet-S and DOV In-Reply-To: <20011017202151.B3144@beverly.kleinbus.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-isdn@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wed, 17 Oct 2001, Ignatios Souvatzis wrote: > But about the 7 of 8 bit part - the US use ulaw encoding - don't they? thats > a 14 bit into 8 bit compression - you need an 8bit channel to transport it. > Unless they are sampling it at 7 kHz sample rate, but famous US ISDN hardware, > e.g. the audio chip used by (now ancient) SUN workstations, only supported > 8 kHz 8-bit uLAW-encoding. The story I heard was that in the past (or maybe even in the present), some long-distance trunks weren't 8-bit clean... they'd steal a few bits for signalling information (or maybe it was to maintain sync... I don't really know :) So, unless you explicitly requested 64kbps unrestricted digital data (i.e. if you requested voice), you might not get an 8-bit clean channel. As far as I know, all local voice bearer calls are 8-bit clean, and some ISDN equipment can make 64k DOV calls. -- Name: Dave Huang | Mammal, mammal / their names are called / INet: khym@azeotrope.org | they raise a paw / the bat, the cat / FurryMUCK: Dahan | dolphin and dog / koala bear and hog -- TMBG Dahan: Hani G Y+C 25 Y++ L+++ W- C++ T++ A+ E+ S++ V++ F- Q+++ P+ B+ PA+ PL++ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message