nicolas@csi.forth.gr (Nicolas Chrissakis) (01/28/91)
Hello TB+ modem users, I have 3 TrailBlazerPlus modems. The modems have prom version 4.00. If I upgrade them to something higher, what will I gain? I know that version 5.0 , has bugs. Version 5.01 is OK. If I upgrade to 5.01 or higher will I gain anything. Thank You for your time. Nicolas Chrissakis Office: +30 81 229368, 229302,221171,229346 Systems Analyst Fax : +30 81 229343, 229342 Foundation of Research Telex : 262389 CCI GR and Technology - Hellas E-mail: nicolas@csi.forth.gr Institute of Computer Science NICOLAS @ ARIADNE P.O.Box 1385, Heraklio, ariadne!nicolas Crete Greece 711 10
cec@public.BTR.COM (Cerafin E. Castillo cec@btr.com) (01/30/91)
In article <1615@ariadne.csi.forth.GR>, nicolas@csi.forth.gr (Nicolas Chrissakis) writes: > Hello TB+ modem users, > > I have 3 TrailBlazerPlus modems. The modems have prom version 4.00. > If I upgrade them to something higher, what will I gain? > I know that version 5.0 , has bugs. Version 5.01 is OK. > If I upgrade to 5.01 or higher will I gain anything. > With the introduction of GF7.00 firmware in the T2500/T1500 modems, connection problems between this firmware level and Telebit modems with BA4.00/BB4.00 firmware have resulted. Two remedies that I have used for this compatibility problem have been S120=16 and BA5.01 firmware. The GF7.00 firmware introduces V.25 tones during a PEP connection in order to survive noise suppressor/compander weaknesses in long distance carriers such as MCI and SPRINT. These weaknesses cause the clipping of PEP packets during transmission due to the 'kicking-in' of the carriers echo suppressors during the silent pauses found between PEP packets. The V.25 tones, found throughout V.32/V.22bis/Bell212/Bell103 modulations, help keep this from happening by causing a constant tone during transmission, no more pauses. BUT, these V.25 tones also cause connection problems with older firmware in TELEBIT modems. S120=16 disables these V.25 tones and allows easy connections to older modems. This might not be suitable for central sites with rotaries on their modem banks. BA5.01 is not phased by these V.25 tones. No changes needed for compatibilty. I suspect that sooner or later, upgrading will be the only answer to this problem, not S120=16. I'm surprised that Telebit has not announced a plan to better deal with this problem. Hope this helps and good luck! =============================================================================== 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..." ===============================================================================