Date: Wed, 11 Jun 2003 15:10:53 +0200 From: Hans Petter Selasky & <hselasky@c2i.net> To: Sergio de Souza Prallon <prallon@tmp.com.br>, Joshua Silver <jaster@shoalhaven.net.au>, freebsd-isdn@freebsd.org Subject: Re: 56k DoV Message-ID: <20030611151053.B20101@curly.tele2.no> In-Reply-To: <20030611011745.A2302@tmp.com.br>; from prallon@tmp.com.br on Wed, Jun 11, 2003 at 01:17:45AM -0300 References: <200306111208.21922.jaster@shoalhaven.net.au> <20030611011745.A2302@tmp.com.br>
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Hi, I wrote the HDLC encoder/decoder. Q.921's definition of HDLC is a serial (1-bit) protocol, that transfers 8-bit units of data. I'd assume this is the same for all transferrates. If I'm right, all you have to do, is to move the bits around, so that the serial data stream is the same. Bits are transmitted in the order bit[0] to bit[7] inclusively (64k). When using 56k there are two logical choices of unused bits: Either bit[0] or bit[7] can be set to either zero or one. According to the HFC-S manual, setting bit[0] (LSB) to one is default when using 56k mode. To decide for sure what format your ISP is using, I'd need a data-stream sample. What version of FreeBSD are you using? On Wed, Jun 11, 2003 at 01:17:45AM -0300, Sergio de Souza Prallon wrote: > Hi, > > I wrote the driver for this card, but I never had any experience with DoV > (it's not an issue in my country). AFAIK, involves "cheating" the bearer > codes (which can be done - there is at least one patch from NetJet Inc > for it) AND (in the 56K case) ignore the 7th bit of every byte sent or > received does not exists while encoding or decoding the HDLC frames. > Unfortunately, this is not handled by the HDLC encoder/decoder package I > use. It may be possible to hack it, but I don't know for sure, the code > is heavily optimized. I'd suggest you to contact Hans Petter Selasky, the > original author of the encoder. > > Hope this helps. > > []'s > > -- > Prallon > > > > On Wed, Jun 11, 2003 at 12:08:21PM +1000, Joshua Silver wrote: > > Hi All, > > > > I have just setup an ISDN connection using a NetJet-S PCI card. Card detects > > fine, and I can make 64k Data calls no prob, but when I try to do a DoV call, > > it don't want to play ball .... dooh .... :( > > > > A little research, and I've found out my ISP uses Ascend MAX 6000's, which > > will only accept 56k DoV, not 64k DoV. I've put the NetJet card into a > > Windoze machine and had the expected results, it does 64k Data calls, it > > fails with 64k DoV, but works fine with 56k DoV, so I know it can work. > > > > The prob I've got is I can't find the relevant bearer cap codes anywhere for > > 56k DoV ... I can find the other two everywhere on the net, 0x8890 for 64k > > Data, and 0x9090A3 for 64k DoV, but can't find any info what the 56k DoV > > setting should be. > > > > I was hoping some one out there has the answer to my problem. > > > > Thanks in advance, > > > > Josh. Yours --HPS
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