dyer@halleys.UUCP (Steve Dyer) (10/27/86)
I am looking for modems which can support rates higher than 9600 baud over 4-wire full-duplex D1-conditioned analog leased lines, aka 3002 circuits. I'm designing a small wide-area network and 9600 baud really won't cut it for the backbone, but 56kb digital service is just too expensive and not cost-effective. Anyone know of modems which can support 19.2kb or higher synchronous rates over fairly long runs (10-50 miles)? -- --- Steve Dyer spdcc!dyer dyer@harvard.harvard.edu
phil@amdcad.UUCP (Phil Ngai) (10/28/86)
In article <28@halleys.UUCP> dyer@halleys.UUCP (Steve Dyer) writes: >I am looking for modems which can support rates higher than 9600 baud >over 4-wire full-duplex D1-conditioned analog leased lines, aka 3002 >circuits. I'm designing a small wide-area network and 9600 baud really >won't cut it for the backbone, but 56kb digital service is just too >expensive and not cost-effective. Anyone know of modems which can >support 19.2kb or higher synchronous rates over fairly long runs >(10-50 miles)? There's this little company in Massachusetts named Codex which makes a product which will do what you want. It is called the 2680 trellis coded 19200 bps modem. It's about $30,000 for a pair. Still think DDS is expensive? -- The VT220 keyboard is an <iS<o standard. That means the French can hate it as well as the Americans. <phil <ngai +1 408 749 5720 <u<uC<p: <[ucbvax,decwrl,ihnp4,allegra<]!amdcad!phil AR<pA<; amdcad!phil@decwrl.dec.com
pag00@amdahl.UUCP (Pria Graves) (10/28/86)
In article <13552@amdcad.UUCP> phil@amdcad.UUCP (Phil Ngai) writes: > In article <28@halleys.UUCP> dyer@halleys.UUCP (Steve Dyer) writes: > >I am looking for modems which can support rates higher than 9600 baud > >over 4-wire full-duplex D1-conditioned analog leased lines, aka 3002 > >circuits. > > There's this little company in Massachusetts named Codex which makes Not so little..... they are part of Motorola -- Pria ...!{ihnp4,hplabs,amd,nsc}!amdahl!pag00 (408) 746 7539 (Disclaimer: even I don't necessarily agree!)
dyer@spdcc.UUCP (Steve Dyer) (10/29/86)
>There's this little company in Massachusetts named Codex which makes >a product which will do what you want. It is called the 2680 trellis >coded 19200 bps modem. It's about $30,000 for a pair. > >Still think DDS is expensive? Right now, I'm finding that 56kb digital service, at least between the points that I'd be interested in, is more than 7X as expensive as analog 9.6kb lines, and the necessity to keep recurring costs low is a major factor in the design. While I'll agree that $30K is a bit steep, I've already received pointers to other modems in the 14.4/16/19.2kb range for a lot less, which information I'll summarize once I sift through it all. -- Steve Dyer dyer@harvard.HARVARD.EDU {linus,wanginst,bbnccv,harvard,ima,ihnp4}!spdcc!dyer
phil@amdcad.UUCP (Phil Ngai) (10/29/86)
In article <4061@amdahl.UUCP> pag00@amdahl.UUCP (Pria Graves) writes: >In article <13552@amdcad.UUCP> phil@amdcad.UUCP (Phil Ngai) writes: >> There's this little company in Massachusetts named Codex which makes > >Not so little..... they are part of Motorola I was being sarcastic, obviously a mistake on my part. -- The VT220 keyboard is an <iS<o standard. That means the French can hate it as well as the Americans. <phil <ngai +1 408 749 5720 <u<uC<p: <[ucbvax,decwrl,ihnp4,allegra<]!amdcad!phil AR<pA<; amdcad!phil@decwrl.dec.com
swb@batcomputer.TN.CORNELL.EDU (Scott Brim) (10/31/86)
Have you considered duoplexers? (two 9.6 lines in tandem to create a logical 19.2 connection)
mark@cbosgd.ATT.COM (Mark Horton) (11/04/86)
I haven't followed it closely, but yesterday a salesperson pointed at a TeleByte modem, said the cost was $3500 each, and that it did 19.2K over regular dialup lines. Part of this is probably done with data compression, so it may not help your application. Also, if you're willing to wait a while, you might be able to use ISDN. That will give you 2 64K switchable circuits over 4 wires. In the US I think you have to be on a 5ESS, but I hear our local 5E is scheduled to have ISDN available in 1987 sometime. Mark