ISDN disconnect problemi

3COM USR ISDN Pro TA S in WinXP (disconnect problem tudi na ostalih OSih)

Kot prvo me zanima sledece.
Zaj sem zacel sistematicno testirat od zgoraj navzdol povezavo ter stabilnost. Sicer se bom vsekakor obrno na telekom ko bom test koncal da nej preverijo ce je linija vredu torej zaj sem zacel to testiranje sledece.

64kbps USB - dol padam random! (lahko po 10min lahko po 2 uri zadnji padec po 1:43)

56kbps (57.6kbps) Com1 - lih kaj testiram

56kbps (38.4kbps) Com1 - sem ze prej testiral delovalo je zelo stabilno. Se enkrat nisem dol pado vendar je hitrost izredna ce ves kaj mislim. Vendar se da kr vredu igrat N4 brez problemov.
Sel bom pa vedno ko me diskonekta en korak navzdol. Na Com1 pa testiram zato ker nemrec na USB nimajo te nastavitve za hitrost modema dobenega vpliva.

Zaj me pa zanima a sploh koristi to kaj na ISDN liniji al samo zapravlam cas?

Nasledna stvar je re-train (sledi razlozitev)

TSCNet's telco service is is a mix of analog (normal modems) and Digital lines (K56flex, ISDN) resulting in our end having the best connection quality the telco is capable of providing to a subscriber. The local exchanges communicate between themselves using digital technology simular to our K56flex, ISDN so there are normally not problems with that segment. This leaves the 'local loop' between the subscriber and their telco central office as the only remaining segment which is likely to affect connection quality. This situation of having 'two thirds' of the connection path be digital, results in calls to TSCNet often training at the maximum speed (115,000/port speed 64Kbps/real speed) the modem will support. But our experience is that the connection will quickly retrain due to the quality of your local loop once data begins flowing between TSCNet and the computer.

You can't detect the retrain, it's something invisible happening between the two modems, but after the retrain the modems are usually running at a different speed. Heavy data flow is the situation most likely to cause a retrain (more data transfer = more data errors = retrain). What's happening is a sort of yoyo effect. The modem trains to a speed which is too fast, data flows, errors occur, the errors trigger the modems retrain to lower speed, resulting in fewer errors, things are good for a while so the modems retrain to a faster speed, where errors start to occur causing the modems retrain.... and so on.

The modems are not supposed to constantly retrain, they have rules in the firmware of the modems to minimize constant retrains... but our experience in the field with this is it happens a lot anyway, especially over longer calls. Retrains are very complex events and some of the most bug infested code in modem firmware, eventually one of the retrains fails and you get disconnected. This is why long file transfers result in disconnects.

So everything was fine, and suddenly you are getting more disconnects. The chances are your phone line quality has changed. It may have gotten slightly BETTER... particularly if it's been dry and/or cold for a little while. Perhaps your line may have gotten slightly worse, for a huge list of reasons but especially if it's been wetter or warmer than normal recently. But just a tiny change either way will simply fool your modem into training to a speed the line will not actually support .... and the retrain problems begin. Have you seen a phone company truck in yur neighorhood lately? This may also be an indicator that something has changed.

You can avoid a lot of disconnect and performance problems by forcing your modem to train up to only a certain speed and no higher. You can't use serial port speeds, the only correct way to control the connection speed is to use modem init string options to disable the modems' ability to train higher than a certain maximum. This can be a rather tedious task... you must figure out where the modem in it string is stored in the software and then you have figure out the actual init option. Determining what value to use can be mostly trial and error... Start with a serial port speed of 38.4K bps and a maximum dial connection speed of 24K bps.

Torej spet ali to velja za ISDN ali ne? Zelo interesanten je zadenj stavek "Start with a serial port speed of 38.4K bps and a maximum dial connection speed of 24K bps"

Torej zakaj ne rece enostavno zacni z Com1 115kbps sej vseeno ani mislim no sej to je samo hitrost vrat torej od modema do racunalnika ko modem ze zdavnej ma podatke. Ali ne?

Prosim kdo koli ve odgovore sej nej ne drzi nazaj

Hvala

Ce imas v nastavitvah
try this string: not to get disconected frequently
S6=S11=S10=50
modem properties/properties/connection/advanced/extra settings

sem tu not napiso se priklopo na 64kbps in 57kbps modem speed in spet po 3 ure in nekaj dol leto.

ja saj oni pravijo da nimajo nic zraven ce si pripravlen verjeti ne! Pol pa kaj bi te lahko telekom sploh naredo? Sicer se bom tak obrno tja. En tip predlaga nekaj v zvezi z NT zascito pri ISDNu da bi jo kr dol vrgo in ta tip je iz telekoma.

Pol se pa nekaj moj modem se nikdar se ni ob disconnectu povezo nazaj vedno pise nekaj v smislo ni se mogo povezat z racunalnikom ki ga klice al pa port je zaseden. Mam tore 3COM ISDN USR Pro TA S in ce pogledas kol pride ta modem te zasuce

in disconnect problem je resen na moji strani! Hvala pametnim glavam na telekomu!