Path: sauna.cs.hut.fi!news.funet.fi!sunic!EU.net!howland.reston.ans.net!cs.utexas.edu!convex!news.onramp.net!usenet From: "V34.VFC LACTT FORUM" Newsgroups: comp.dcom.modems Subject: V34.VFC (L-A-C-T-T!) FORUM-Let'sAvoidalltheConfusionThisTime!) Date: Mon, 20 Jun 94 08:25:31 PDT Organization: On-Ramp Technologies, Inc. Lines: 150 Message-ID: <2u4dqb$7rp@news.onramp.net> NNTP-Posting-Host: dal01.onramp.net Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII To: v34 Bcc: v34 , v34 , v34 , Pro Systems Technology Cc: bpechey@hayes.com X-Newsreader: NEWTNews & Chameleon -- TCP/IP for MS Windows from NetManage ================================================================== T H E V.34/V.FC L-A-C-T-T F O R U M * L-A-C-T-T - Let's Avoid all the Confusion This Time! ================================================================== New --- from A Hayes fellow "IN THE KNOW." He pesents a very thorough description of the current status of 28.8 V.34 and the differences vs. V.FC. ---Dennis (djv)--- ================================================================== ---------------Original Message--------------- In-Reply-To: Dennis, It's not absolutely clear that you intended to send your mail message to me but I thought I'd reply anyway! [yes--I hoped you would--djv] The V.34 facts are: The V.34 document was approved by ITU-T Study Group 14 on Thursday 9th June for the letter ballot process where all voting members of the ITU-T are invited to vote on its adoption as a fully-ratified Recomendation. Incidentally, the only members of ITU-T that have a vote are what ITU call Administrations; these are almost the same as countries. USA gets a vote, UK gets one etc. Modem companies don't have a vote at all. The letter ballot process will take about 2-3 months. However, none of these letter ballots has ever rejected something approved by a Study Group. Rejection needs about 40% NO votes of those replying. Consequently it is pretty safe to assume that all that stands between the current document and V.34 is the passage of time. This means that companies are confident to announce V.34 modems right now. The V.34 document is more than 70 pages in length and is VERY mathematical and also, believe it or not, terse. There is very little explanatory text. It is likely that there are bugs still in it and we may need to have a revision in the next year or so. I hope these bugs will only be editorial ones although the scope for ambiguity is great as in any complex standard of this length. The V.FC/V.34 facts: The first V.FC modems were shipped in November 1993 and there have been many, many thousands sold. The idea behind V.FC was to take some of the techniques being proposed for V.34 and put them into a real modem that people could use. This also gave a lot of people the opportunity to try out 28.8 kbit/s operation for the first time. There was never any intention from Hayes or Rockwell (who worked together for two years on V.FC) that V.FC would be compatible with V.34 - even if we had wanted it the others would have made sure it didn't happen! In fact, we made the start-up deliberately different from V.34 so that it would be easy to distinguish between the two and easier to make dual-mode V.FC/V.34 modems. We learnt a lot about the special techniques and a lot abou the phone system. V.FC is quite different from V.34 if you look at the specs; most of the signal-processing algorithms, whilst based on the same theory, are implemented in different ways. The range of speeds supported by the two is different (2400-28800 V.34, 9600-2880 V.FC). V.34 has some extra things like a secondary channel and a special mode for 28.8 kbit/s fax. The Rockwell V.FC implementation uses a single-chip mask programmed DSP for all the signal processing functions. You can also buy a modem controller chip from Rockwell to go with it which implements AT commands, error-control, compression etc. Hayes didn't take that, we made our own controller using the Motorola 68302 processor. This makes for a low-cost, high-performance modem implementation. Obviously, when it comes to an upgrade from V.FC to V.34 you have to have a new, masked DSP chip plus, of course, new controller firmware to implement all the V.34-specific stuff. This means that the upgrade process for Rockwell-DSP based modems has to be a return-to-base process. How suppliers handle this is up to them; some will pre-ship (with certain guarantees); some will insist on upgrading the actual product sent in rather than doing a swap. This is not so convenient as downloadable firmware but it isn't too bad; you do also get the benefit that the modem you get back has been through a full re-test and any faults will have been fixed. Some countries' regulatory authorities do not permit users to upgrade modems in this way. Remember that the upgraded modems will talk to either V.FC or V.34 modems. Personally, I would be wary about buying a V.34 modem in the next few months; the spec is so complicated there are many things that you can implement incorrectly. These may appear as interworking issues with other suppliers or performance significantly worse that the theoretical. In the past, it has taken a few months for suppliers to wring this type of bug out of their products. Look carefully at firmware revision numbers! If you must have 28.8 kbit/s now get a V.FC with an upgrade promise and make the upgrade when you think things have shaken down - you'll have a lot more modems to talk to! I have heard it said that there will be in excess of a million V.FC modems installed by the end of 1994. Hope this [HELPS] straighten things out. Bill. PS. This is intended for your information but if you want to distribute it further I would like to know ahead of time and I would not want it edited. [PERMISSION GRANTED IN DIRECT E-MAIL -- djv; see append below. ] Bill Pechey Tel: +44 252 775513 (direct) Hayes Microcomputer Products, Inc. Fax: +44 252 775511 Millennium House Telex: 859066 HAYES G Fleetwood Park 9312133830 HA G Fleet Compuserve: 71601,2572 Hants Dialcom: 74:HAY001 GU13 8UT Usenet: bpechey@hayes.com United Kingdom bpechey@ibmpcug.co.uk bpechey@cix.compulink.co.uk ----------End of Original Message---------- Regards, -Dennis --- þ POW 1.0 On Trial þ Powerline Offline reader for Windows - New Windows OLR ================================= 06/20/94 Dennis, OK, you can put it out but please say who it's from when you do. I've talked to people in Hayes and they're happy. Best wishes, Bill. PS. Please quote my address as bpechey@hayes.com but don't change the address you use for this list - hope that makes sense!Reason is that the Hayes computers only have dial-up Internet access whereas CIX has direct connection. ================================= <<>>===================================<<>> <<>> name: Dennis J. Van Dine <<>> <<>> company: Pro.Systems.Technology <<>> <<>> e-mail: ProSysT@onramp.net <<>> <<>> address: 3900.N.Garland.Ave <<>> <<>> city/st: Garland.TX.75040 <<>> <<>> phone: 214.414.5302 /9474.fax <<>> <<>>===================================<<>> <<>> Remote-Desk-Interfaces & SW <<>> <<>> .Computer Personal Training. <<>> <<>> ........AT&T Modems......... <<>> <<>>===================================<<>>