Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!mips!public!cec From: cec@public.BTR.COM (Cerafin E. Castillo cec@btr.com) Newsgroups: comp.dcom.modems Subject: Re: net-blazer queries Summary: Answer to inquiry & CSLIP (detailed)... Message-ID: <1507@public.BTR.COM> Date: 29 Jan 91 19:00:13 GMT References: Organization: BTR Public Access UNIX, MtnView CA, Contact: cs@btr.com 415-966-1429 Lines: 61 In article , mrapple@quack.sac.ca.us (Nick Sayer) writes: > > Our site currently has a 9600 baud internet link that has about > a 300 msec ping time to the opposite end of the link, and > a 450 msec ping time to uunet. We aren't particularly happy > with that and would like to see what improvements we can make. > The link itself is a voice-grade audio, plug-in-two-telephones- > and-talk leased line. > > I've heard good things about the netblazer... > > [deleted] I would agree that V.32bis might give better performance to a SLIP link, but I have not heard of any users actually using a REAL V.32bis modem (all I have seen are ads...). A full-duplex, high-speed modulation and V.42/V.42bis yield the best connection. I have used V.32 with V.42/V.42bis and have found it the best combination, so far. TELEBIT's PEP tends to be jerky and slow due to its half-duplex (aka Adaptive duplex) which uses packets to deliver data. These same packets cause thrashing in SLIP packet vs PEP packet allocation during the link. My recommendation would be the use of CSLIP or PPP with compressed IP, if possible. AlterNet (aka UUNET) should have CSLIP ability through their Annex terminal servers, I may be mistaken though. CSLIP's reduced IP header size gives much better performance than SLIP (unless you are running it using a STREAMS driver...:-(. CSLIP and V.32+V.42/V.42bis makes for an effective and reliable link! As for the Telebit NetBlazer, it offers SLIP/CSLIP/PPP connectivity. The performance is the same as SLIP/CSLIP/PPP using a modem and the serial I/O ports on your UNIX system, when using a single pair of modems. The Netblazer makes setting-up and maintaining a dial-up IP connection much easier. TCP/IP Inverse Muxing allows the use of multiple modems to build more bandwith (and throughput). For example: 6 modems x 9600 bps/each yields about 57.6 kbps. The only drawback is that you need NetBlazers and modems on both sides. At $3793* per NetBlazer and about $795 (T1600 list) per modem, this could get expensive (Phone line and line costs, not included...). If AlterNet uses the NetBlazer this could facilitate things on your end, when using dial-up IP. Of course, it would be interesting to see what AlterNet charges for TCP/IP Inverse Muxing connections... I would start with CSLIP and V.32/V.32bis (+V.42/V.42bis) modems. If this doesn't hack it for you, then I'd consider whether I would stay with modems and dial-up IP or switch to a 56kbps/T-1 connection to the Internet. Hope this helps and good luck! *List Price for NetBlazer 10-port (ie N10-1E). =============================================================================== Cerafin E. Castillo || //\\ ||\\ || Network Consultant || //__\\ || \\ || Los Altos Los Altos Networks || // ---\\|| \\|| Networks 340 Second St. #6 ||___// \ | \ | Los Altos, CA 94022 (415) 941-8031 UUCP: {apple,sun,uunet}!portal!cup.portal.com!cec INTERNET: cec@cup.portal.com "...No hay mal que por bien no venga..." ===============================================================================