---

Filename: 9600DATA.TXT Version : 1.2b Updated : 1/11/1991 ------------------------------------------------------------------------------- A Comparison of High Speed Modems Compatibility/Features/Differences/Prices Including: HST, V.32, V.32bis, V.42, V.42bis By Mike Ehlert, SysOp: PACIFIC COAST MICRO BBS USR HST/V.32bis (805) 494-9386 USR HST 14.4k (805) 497-3456 CC Speedmodem (805) 496-7320 FidoNet 1:206/2801 ------------------------------------------------------------------------------- TABLE OF CONTENTS A High Speed Modem Disclaimer Standards The CCITT Half-Duplex Vs. Full Duplex What is MNP, HST, V.32, V.42 etc. What to look for: Throughput, Configurability, UARTS, etc. Some Questions to ask: If Considering a generic V.32/V.42. Some Questions to ask: If Considering a FAX/Modem. Modem Manufacturer Phone Numbers. Modem Compatibility Listing. Modem Price Comparisons. Document Updates. ------------------------------------------------------------------------------- A High Speed Modem ================== Are you thinking of going to a High speed modem? 2400 baud can be very slow for transferring large files. Modems advertised as 4800 are really only 2400 with data compression such as MNP-5 or even just software data compression. Don't be fooled. A 9600 or faster modem will make a tremendous difference on your transfer time. Most 9600 Baud users never want to go back to 2400. There is a lot of confusion and mis-information about 9600 Baud and faster Modems. I wrote this to help clarify and point out the differences between the different modems available for MS-DOS machines. If price is no object, the Best modem to get for BBS use is the US Robotics Dual Standard. It is a combination of the HST 14400 Baud modem and a V.32/V.42 modem all rolled into one modem. If price is an Issue, (like it is to most people) then you may want to consider a Standard HST 14.4k, or a different Brand if that is also too expensive. But if you do not buy a US Robotics Modem, you will not be able to hook up to a Standard USR HST 14.4k, which is the most Common BBS Modem. Other then USR, you could get a V.32 or V.32/V.42 computable modem for about 25% less then a Standard HST, or you could get a 9600 FAX/Modem for less then half the cost of a V.32 See the price comparisons at the end. ------------------------------------------------------------------------------- Disclaimer ========== This information was obtained from several reputable sources, but none of it is guaranteed to be 100% accurate. I am not responsible for any incorrect information in this document, nor am I responsible for any loss of profits to anyone resulting from reading the information in this documentation. Proceed at your own risk. ------------------------------------------------------------------------------- Corrections and updates ======================= Since new modem brands, models, and new prices are appearing constantly, this documentation is going to need a lot of updating. Also some of the Current Information may need corrections as well. You are welcome to make changes to this information, but please send me a copy of your update so that I can add your changes to the current latest version I have. That way all the corrections that are made will be added to the latest version, which will also be avail. for download on my bbs. ------------------------------------------------------------------------------- STANDARDS ========= At one Time Hayes was the standard in modems. All other modems tried to be "Hayes Compatible". This is still true with 1200 and 2400 bps modems, but NOT when it comes to 9600 or faster modems. Hayes established a Standard called the AT command set. Other modem manufacturers quickly adopted this standard and the AT commands are still used today (with a few commands added). Well Along Came USRobotics, and designed the HST, a proprietary 9600 modem that quickly became popular, and no one else was allowed to duplicate. Hayes then also came out with a proprietary 9600 modem, but since it could not talk to the HST at 9600 it never became popular in the IBM world. Next USR improved their HST modem, making it transfer at 14400 bps without even using data compression. USR's HST became the standard for MS-DOS computable High Speed modems. Realizing that the industry needed a "non-proprietary" 9600 standard that any manufacturer could use, the CCITT came up with the V.32 specification. It took a several years before modem manufactures started finding ways to implement this standard at a price competitive to HST, but a few manufactures started producing them, including Hayes. Next the CCITT realized that better error correction and data compression methods existed, and thus came up with the V.42 and .V42 bis standard. They are currently finalizing the V.32bis specification, which will also run at 14,000 Baud in full duplex. Now Modem Manufactures all seem to be jumping on the V.32 Bandwagon, Even USR offers V.32/V.42 modems and allows the HAT's to be upgraded to a "Dual-Standard" so it can be both HST and V.32/V.42 in one. The New Hats also have V.42bis and can be upgraded to the new V.32bis DS. The price Difference between the HST and the HST-DS is considerable though, which is why Most BBS Sysops still buy the HST without the "DS" option. The V.32/V.42 have become the standard in the Macintosh world, and some MS-DOS BBS's are now running V.32/V.42 instead of supporting the HST, and some are supporting both types, using multiple lines. Fax Machines have had their own standards, CCITT V.27, V.27ter, and V.29 define the modulation scheme used for Fax, and T.30 defines a Fax Protocol. Fax Machines nowadays can transfer Faxes at 4800 or 9600 Baud. Most Fax/Modems can only transfer files at 2400 Baud. There is now one Fax/Modem which can also transfer files at 9600 bps, and is far less expensive then the V.32/V.42s, plus offer the benefits of a Fax machine. --------------------------------------------------------------------------- The CCITT ========= The International Consultive Committee for Telegraph and Telephone (CCITT) set the V.32, V.42, and V.42bis Standards in 9600 bps communications. They have also set the standards of 1200 and 2400 bps in Europe. Unfortunately the V.32 standard is very expensive to implement for the modem manufactures, and the HST has already become the industry standard in the IBM BBS world. But since any company may manufacture V.32/42 Modems without a license or royalty, there is more price-competition going on with these then with the HST, which currently has no true competition. ----------------------------------------------------------------------------- Half Duplex Vs. Full Duplex =========================== Half-Duplex is When Data is Transited in one Direction at a time. Full-Duplex is both directions at once. 2400 baud modems are Full-Duplex. The HST Modem uses an improved form of Half-Duplex, in which one direction is transferring at high speed while the other direction is sending ACK/NAK signals at a slower speed. A similar method is used on the Speedmodem. V.32 modems use Full duplex, which in most cases does not improve performance when used on a BBS. There is one way to take full advantage of a Full-Duplex Modem: By using a protocol called Bimodem to upload and Download as the same time at 9600 bps in each direction! Unfortunately Bimodem has not become very popular. Most BBS's and users still use one direction transfer protocols such as Zmodem or YModem-G. ------------------------------------------------------------------------------- What is MNP, HST, V.32, V.42? ============================= MNP MNP (Microcomm Network Protocol) levels 1-4 are methods of error correction in which the two modems connected verify the integrity of the data transmitted. Error correction is required for several streaming protocols such as Ymodem-G in which the protocol sends a constant stream of data and lets the modems do the error correction. This requires a clean, noise free line as streaming protocols will abort if line noise interferes too much. These MNP Levels are used in almost all High Speed Modems Made today, But Just because two modems both have MNP it does not ensure that they will both talk to each other (at over 2400 baud). MNP Level 5 is for data compression. Since All BBS's have their files archived in ZIP, LZH, GIF or some such compressed format (try to ZIP a LZH file), MNP5 can actually increase the overhead by attempting to compress the file further. Therefore BBS's leave MNP5 turned off, and so should the BBS callers. ------------------------------------------------------------------------------- HST HST stands for "High Speed Technology" - a method of communicating at high speeds which was developed by US Robotics in 1984. HST is a proprietary method so currently only US Robotics is allowed to Make HST Compatible Modems. The original HST modems were 9600 bps by using a 9200 bps channel in one direction and a 450 bps "back channel" in the other to send ACK/NAK signals for confirmation of data - a half duplex mode - often referred to as "ping-ponging". In 1989 USR improved the HST to run at 14400 bps by further optimizing their proprietary method. All HST's sold now include the 144k speed as well as the original 9600 mode. Because the HST 14.4k is a raw speed, It allows the HST to transfer pre compressed files such as ZIPs at faster speeds then any other 9600 modem: over 1700 Characters per second. The HST has become the "BBS-Standard" in high-Speed Modems. More BBS's use the HST then any other type of modem, including the V.32. As of January 1st 1991 all HST modems also include the V.42/V.42bis error correction and data compression (not to be confused with V.32). The HST's can also be upgraded to the HST "Dual Standard" allowing it to also be V.32bis compatible. The price is significant for this upgrade however, and in very few cases is any speed gained. ------------------------------------------------------------------------------- V.32 V.32 is a 9600 Baud standard that was established by the CCITT back in 1984. V.32 is full duplex (9600 bps in both directions at once). Normally this would be impossible, but using a technique called "echo cancellation", one modem can filter its own tones from the phone line, enabling it to pick out the signals from the other modem. However, echo cancellation requires that high speed modems include built-in digital signal processor (DSP) chips, which is the main reason V.32 and V.42 costs so much. V.32 also includes a fall back to 4800, if line noise becomes a problem at 9600. The V.32 standard also provides an optional error-reduction scheme, called "trellis-coded modulation (TCM). TCM allows 9600 modems to check for transmission errors with a redundancy bit, which results in fewer errors on noisy lines. Most V.32's include this option, but some do not. ------------------------------------------------------------------------------- V.32bis It was first realized in 1989 that it is feasible to push V.32 up to 14,400 baud, the same speed as the HST now runs. This requires even better echo cancelers and an overall improvement in receiver quality, so it will be more costly to produce than the V.32 to produce. V.32bis has not yet officially been finalized CCITT, but as of January 1st US Robotics has started shipping a new version of their Dual Standard Modem which includes V.32bis in an early but functional form. USR plans to update their DS ROMS when the CCITT actually release the completed V.32bis specification, scheduled for mid 1991. It's expected that other Modem manufacturers will not be able to offer the V.32bis technology until the 4th quarter of 1991. ------------------------------------------------------------------------------- V.42 V.42 is nothing to do with actual modem speed, but how the error correction and data compression schemes interface. When the CCITT approved V.42 in 1988, they decided to include two different error correction and data compression schemes. The first one is MNP,(short for Microcom Networking Protocol). MNP classes 2, 3, & 4 which handle error correction. Note that MNP-5 was not included in the V.42 standard because it is only used for data compression. MNP was made an official standard due to the large number of modems that currently use it. The Second method is the preferred method, known as LAP-M (Link Access Protocol-Modem). A modem with only MNP is called "V.42 Compatible" and one with LAP-M its known as "V.42 Compliant". If a V.42 Compliant connected to a V.42 compatible, it would first try to Handshake with LAP-M, and after it realized that the other modem is not Compliant, it would try the MNP Method, and they connect. Most V.42 modems are fully V.32 compatible, but they do NOT have to be, according to CCITT guidelines. So when purchasing a V.42, make sure that it is really a V.32 Modem that is also V.42 compliant or compatible. There are now some 2400 baud modems which are also V.42bis compliant, so since the LAP-M gives 4:1 data compression they are advertised as "9600 throughput", which really can be misleading and confusing. ------------------------------------------------------------------------------- V.42bis V.42bis is a new CCITT standard for data compression techniques, which was approved in late 1989. To Support V.42bis, a modem MUST support both LAP-M and MNP-5, unlike the Standard V.42 in which LAP-M is only an option. V.42 provides a maximum data compression of 4:1, giving a 9600 bps modem a throughput up to 38400 bps. MNP only offers 2:1 Compression. Like MNP-5, LAP-M and V.42bis will not be effective when transferring compressed files from BBS's, such as ZIP files. Since V.42 is implemented in firmware, many V.42 compliant modems can be upgraded to V.42bis with a new ROM. ------------------------------------------------------------------------------- Speedmodem A less expensive method of 9600 bps communication can be achieved without using the CCITTs method of "echo cancellation", so that the a digital signal processor is not needed, making the cost much less expensive. This method is used on the Compucom Speedmodem. The Speedmodem also uses Dynamic Impedance Stabilization (DIS) to increase the reliability of the telephone interfaces signal-to-noise ratio of the telephone line by increasing the clarity and power of the signal, and automatically compensating for impedance variations on the phone line. This reduces the probability of line noise, allowing the Protocols to transfer files with less overhead It also has a faster fall back rate of 7200 bps if too much line noise exists for 9600 communications. This makes the Speedmodem stand up to worse line noise conditions at a faster rate then V.32 can handle. The Speedmodem is also a 9600 bps Group III Facsimile, so with this modem, you can send document and scanned images as a Fax, as well as receive Faxes. It supports BitFAX by Bitcom and any other 3rd party FAX software which uses the standard CCITT AT-FAX command set. A Data Compression called CSP (CompuCom Speed Protocol) is used to yield a compression of up to 4:1, giving a throughput of up to 38400 bps. This however, like MNP5 will not be effective when transferring compressed files from BBS's, such as ZIP files. DIS and CPS are proprietary methods owned by CompuCom, Sunnyvale, CA. Because this modem is inexpensive more people can afford to buy it, and since its both a FAX and a Modem in one, it should gain popularity quickly. It is still a new product, but hundreds of BBS's are showing support for it. ----------------------------------------------------------------------------- What Next? By mid 1991 the V.32bis standard will be finalized, and by that years end the several 14,400 Bps full duplex modems will be on the market. There is already talk of the CCITT releasing another standard in 1992, which will be for 192,000 bps. Since these modems are expected to cost considerably more then the V.32s currently on the market, they will be out of the price range of most BBS users. ----------------------------------------------------------------------------- WHAT TO LOOK FOR THROUGHPUT: ========== You'll see ads claiming that you can attain 19,200 bps or 38,400 bps with a 9600 Baud modem - this is true only if you are using MNP5 or other form of data compression on an uncompressed data or text file. Any 9600 Baud modem using compression will transfer at that effective rate. But for BBS use, where files are already compressed (such as ZIPs, LZHs, GIFs) MNP5 will actually slow down throughput by attempting to compress a file that is already compressed. Generally when using a modem for BBS transfers, its the RAW speed of the Modem and not the throughput which is important. Figures of around 1700 cps by the HST modems are attained through proprietary methods not available on other modems. CONFIGURABILITY: ================ In High Speed Modems, there is a lot more to configure than on a 2400 Baud modem. Be sure your modem comes with NRAM (Non-volatile Random Access Memory) that can store your modem configuration, making long init strings unnecessary. Also many modems have dip switches to set the default configuration, which also simply things. If you buy an Internal Modem, be sure its fully Configurable as far as selecting the com port and IRQ (interrupt request) setting. Some modems can be addressed from Com1: up to COM8: UARTS ===== Internal Modems have a serial port built in, and External Modems use an existing Serial Port in the computer. A serial port has a UART chip to buffer and control the Input/Output (I/O). The XT usually has an 8450 UART which will handle up to 9600 Baud. The AT usually has the 16450. If you have an external modem you should replace your UART with the 16550 (NS16550AN). INTERNAL or EXTERNAL ==================== MS-DOS Users can choose internal modems, that plug in a computers slot, or external, which plugs into an existing serial port with a serial cable. Internals are usually less expensive, take up less space, have the correct UART already installed (see below) and don't need a cable. But the Externals usually have a lot of little lights on it that you can stare at, and its easier to move to another machine. So which ever you prefer (or is available in some cases). If Considering a USRobotics Modem ================================= You only need to worry about weather you want the HST (which can be upgraded later), or the Dual Standard which is the same modem with the V.32bis option included. If Considering a V.32/V.42 Modem ======================================== Some questions to ask: Can you afford the USR "DS" instead? Is it both V.32 and V.42 compatible? Is it V.42 compatible, V.42 compliant, or V.42bis? If its not V.42bis or compliant, can it be upgraded? Do Local/National BBS's support it? Would you rather wait a year for a V.32bis? What is the warranty? 5 years? If Considering a FAX/Modem ============================== some questions to ask: Is it Send and Receive Fax? Does it support 3rd party FAX software? Is it 4800 or 9600 bps? Does it support MNP? Does it support other compression? Do Local/National BBS's support it? What is the Warranty? 5 Years? --------------------------------------------------------------------------- Modem Compatibility Listing: ============================ These modems will usually be downwardly compatible with 2400 Baud and slower modems, Which means they are also CCITTY V.22bis and Bell 103/212A compatible. Most have an auto-fall back mode that will detect the highest negotiable Baud rate, which can either through hardware or software configuration. If the modem is V.42 capable, it will fall back to MNP if the other modem is not LAP-M capable, but is MNP capable. Modems supporting MNP will connect with data compression/error correction with other MNP modems at the highest Baud rate negotiable between the two. The speeds listed here are the actual Raw speed, not possible throughput that can be achieved using data compression. Listed in alphabetical order by brand name - Generic V.32 only Made by a number of companies using the CCITT method of communicating at 9600 bps. These are expected to become outdated as V.42 is added to most V.32 modems - Talks to other brand V.32 modems at 9600 Baud. Generic V.42 Only If a Modem is V.42 or V.42bis only, and not V.32, then it can only talk to other V.42 modems at 2400, (with 9600 throughput using data compression) This is not considered a 9600 Modem and should be avoided. - Talks to other brand V.42 modems at 2400 Baud with LAP-M. Generic V.32/V.42 (and V.42bis) These modems follow BOTH the CCITT V.32 and V.42 standards for communicating at 9600 bps. - Talks to other brand V.32 modems at 9600 Baud. - Talks to other brand V.42 modems at Top Supported Baud. (Some Generic Brands include: Anderson Jacobson, Codex, Computer Peripherals, Digicom, E-Tech, Farallon, Fastcomm, General Datacom, Intel, Magic, Mastercom, Microcom, Multi-tech, NEC, Practical Peripherals, Prometheus, Radcal Vadic, Shiva, Telebit, Telenetics, USD, and many others just appearing Some of these offer LAP-M and V.42bis, and some do not.) Hayes V-Series: The early Hayes V-Series uses a proprietary method of communicating at 9600 bps. - Talks other Hayes V-Series modems at 9600 Baud. Hayes V-Series V.42: The Hayes V-Series V.42 uses the proprietary method of communicating at 9600 Baud but will incorporate the V.42 data compression and error checking - Talks to other V.42 modems at 2400 with error correction/compression. Talks to other MNP modems at 2400 using error correction/compression. Talks to other Hayes V-Series at 9600. Hayes ULTRA: Uses CCITT V.32 and V.42bis method for communicating at 9600 Baud. Has MNP5 abilities. Has LAP-M abilities - Talks to Other V.32 modems at 9600 Baud Talks to other V.42 modems at up to 9600 Baud Talks to other Hayes V-Series at 9600 Telebit Trailblazer: Uses proprietary PEP method of communicating at 9600 Baud. Has MNP5 abilities. - Talks to other Telebit Trailblazers at 9600. Talks to other MNP modems at 2400 baud with error correction/compression USR Courier V.32: Uses CCITT V.32 and V.42 method of communicating at 9600 Baud. offers MNP5 abilities. - Talks to Other V.32 modems at 9600 Baud. Talks to Other V.42 modems at up to 9600 baud USR Courier HST: (old version) Uses the USR proprietary HST method of communicating at 9600 Baud. Has MNP5 abilities. - Talks to HST type modems at up to 9600 Baud. USR Courier HST 14.4: Uses the USR proprietary HST method of communicating at 9600 Baud. Has MNP5 abilities. - Talks to HST DS's at 14,400 Baud Talks to HST 14.4's at 14,400 Baud Talks to HST's at 9600 Baud USR Courier HST DS: The Dual Standard incorporates both the proprietary HST method of communicating at 14400 baud and the and the CCITT V.32 & v.42 methods of communicating at 9600 Baud. (and V.32bis after 1/1/1991) Has MNP5 abilities. - Talks to Other V.32 modems at 9600 Baud. Talks to Other V.32bis modems 14,400 Baud. Talks to Other DS's at 14,400 Baud Talks to 14.4 HST's at 14,400 Baud Talks to old 9600 HST's at 9600 Baud. COMPUcom Speedmodem/Fax: Uses the Proprietary DIS at 9600 Baud. Has 7200 and 4800 Baud Fall back Has CCITT FAX V.27ter & V.29 Has MNP5 abilities. Has CSP abilities. Talks to Group III Faxes at 9600. -Talks to Speedmodems at 9600. Talks to other MNP modems at 2400 with error correction/compression ----------------------------------------------------------------------------- Manufacturer Toll Free Charge Call Support BBS ============ ============== ============== ============== Anchor (800) 541-2318 Anderson Jacobson (800) 438-8520 (408) 435-8520 Codex (508) 261-4000 Compucom (800) 228-6648 (408) 732-4500 (408) 738-4990 Computer Peripherals (800) 854-7600 (805) 499-5751 (805) 499-9646 Digicom (800) 574-2730 E-Tech (408) 982-0270 Farallon (415) 596-9100 Fastcomm (800) 521-2496 (703) 620 3900 General Datacom (203) 574-1118 Hayes (800) 241-9625 (404) 441-1617 (800) 874-2937 Intel (800) 538-3373 (503) 645-6275 Magic Modems (800) 622-3475 Mastercom (213) 834-6666 Microcomm (800) 822-8224 (617) 551-1000 Multi-Tech (800) 328-9717 NEC (800) 222-4632 (408) 433-1250 Practical Peripherals (800) 442-4774 (818) 706-0333 Prometheus (800) 477-3473 (503) 624-0571 Radcal Vadic (800) 482-3427 (408) 432-8008 Radcal Milgo (800) 327-7909 (305) 846-1601 Shiva (800) 458-3550 (617) 864-8500 Telebit (800) 835-3248 (408) 734-4333 Telenetics (800) 822-4267 (714) 779-2766 USD (800) 631-4869 (205) 430-8000 USRobotics (800) DIAL-USR (708) 982-5001 (708) 982-5092 ---------------------------------------------------------------------------- Price Comparisons ================= No Prices have been stated above this Section, because prices often change, and I want to keep all the prices together so they could be quickly updated as needed. There are 3 types of prices I will cover. First is The Retail price, second is the Sysop price, which is only available if you run a BBS. Many Modem Manufactures offer BBS Sysop special prices directly, at about 50% off the retail price. First the BBS has to be verified, so the modem manufacture knows that is a real BBS that has been running for at least 6 Months, and has a minimum number of users, etc. Usually the Manufacturer will call the BBS once, or twice a few week apart to be sure. Verification usually take 3-4 weeks. Then the Sysop has to agree to use the Modem on the BBS for some set amount of time. ----------------------------------------------------------------- Generic Brands Retail Sysop V.32 Only EXT $650-$1,000 ???? V.32/V.42 EXT $700-$1,000 ???? V.32/V.42bis EXT $700-$1,200 $339+ Software Included: Varies Warranty: Varies 1-5 years ----------------------------------------------------------------- Hayes Retail Sysop Ultra V.32/V.42 $1,199 $599 V-Series V.42 (not V.32) $999 $499 V-Series 9600 $799 $399 Software Included: None Warranty: 2 years ----------------------------------------------------------------- Compucom Retail Sysop SpeedModem/Fax INT $279 $169 Software included: BitFax Warranty: 5 years ----------------------------------------------------------------- Intel Retail Sysop 9600EX $799 $399 Software included: None Warranty: 5 years ----------------------------------------------------------------- Practical Peripherals Retail Sysop V.32/V.42 EXT $699 $339 V.32/V.42 INT N/A N/A Software Included: None Warranty: 5 Years Note: Due to many reports of Incompatibilities/Problems from Owners of these new P.P. Modems, I would not currently recommend them, although they are currently the lowest priced V.32 I have seen. ------------------------------------------------------------------ Telebit Retail Sysop T1000 ??? ??? T1500 V.32 ??? ??? TrailBlazer INT ??? ??? Trailblazer EXT ??? ??? T2500 V.32/V.42 ??? ??? Software Included:None Warranty: 5 years ------------------------------------------------------------------ USRobotics Retail SysOp Courier Dual Standard E $1,595 $699 Courier Dual Standard I $1,395 $649 Courier V.32/V.42 EXT $1,099 $599 Courier V.32/V.42 INT $949 $577 Courier HST 14.4 EXT $995 $449 Courier HST 14.4 INT $895 $405 DS Upgrade Kit for HST EXT $600 $300 DS Upgrade Kit for HST INT $500 $250 Software included: None Warranty: 2 Years ------------------------------------------------------------------ Document updates: Date Release Comments ---- ------- -------- 10/30/90 1.0 Initial Release. Should have run a spell checker! 11/08/90 1.1 Spelling fixes, V.32bis update, Compucom update 01/10/91 1.2 USR V.32bis Update, other minor corrections 01/11/91 1.2b Speedmodem Corrections submitted to Remco Treffkorn for feedback (not for public release) 01/19/91 1.2c Ran the spelling checker through this unbelievable document. Some of the spelling is still wrong like "weather" for "whether." (T. Rosen)

---

The views and opinions stated within this web page are those of the author or authors which wrote them and may not reflect the views and opinions of the ISP or account user which hosts the web page. The opinions may or may not be those of the Chairman of The Skeptic Tank.

Return to The Skeptic Tank's main Index page.

E-Mail Fredric L. Rice / The Skeptic Tank