nghiem@walt.cc.utexas.edu (Alex Nghiem) (08/06/89)
In article <2016@netcom.UUCP> onymouse@netcom.UUCP (John DeBert) writes: >in article <13971@jumbo.dec.com>, ygil@jumbo.dec.com (Joseph Gil) says: >> >> I ordered an MNP level 5 modem from a store nearby. They came up with a >> PcWorks modem that is claimed to be MNP level 7. The thing had only one >> flyer of documentation, and nothing was mentioned there about MNP. If there is no mention of MNP in the documention, then it probably is not one. It is impossible to use MNP features if you do not have access to documentation >> Now my questions: >> >> 1) I understand that MNP level 4 stands for error-correction >> protocol, and level 5 adds data compression. Am I wrong? Correct. Most low cost 2400 baud modems have MNP 3 or MNP 4. MNP 5 represents data compression of approximately 2:1 (2400 baud == ~4800 baud throughput) MNP 4 may support limited data compression, but MNP 5 is the accepted compression standard. >> 2) Is level 7 a super set of level 4 and 5? Yes. (theoretically, there are always bugs in people's implementations) MNP 3 and 4 are usually found in low cost 2400 baud modems. MNP 5 is the accepted standard and represents 2:1 compression. MNP 6 and MNP 7 are usually found in ping-pong (v.29) modems that can transmit with a throughput between 9600 and 17k baud. There is no MNP 8. MNP 9 is found in Microcom's v.32 modem. (4:1 - 5:1 compression) >> 3) How can I check what level the modem is? I have currently no computer >> to test it with. Should be marked in the modem or the documentation. You should be able to find a response-code message that indicated the mode you are in >> >> 4) Can a price of 116.48$ be right for 2400 baud mnp level 7 modem or is >> it another "sales person idea"? Looks like he's trying to sucker you. MNP 7 is usually found in modems that transmit 9600 baud and above. >> I would appreciate any help, and if at all possible before monday, because >> I promised an answer to the shop by then. >> >> >> Many Thanks! MNP stands for Microcom Networking Protocol. Microcom has an 800 technical support number. You should be able to find it in 800 information 800 555 1212. nghiem@walt.cc.utexas.edu !cs.utexas.edu!ut-emx!walt!nghiem "The difference between a computer saleman and a used car salesman is that the used car salesman knows when he is lying." --unknown.