5.577 bytes |
Service Hints & Tips |
Document ID: LWIK-458KXF |
TP 600,770 - Problems connecting at V.90 speeds or low V.90 connection speeds
Applicable to: World-Wide
SYMPTOM:
Getting V.34 connections, 31.2kbps or less, using TP V.90 modem.
Getting V.90 connections at lower V.90 speeds, around 32kbps.
CONFIGURATION:
TP 600 or TP 770 with V.90 modem upgrade installed.
Note: Not all ThinkPad 600's or 770's come with an ACP modem.
WORKAROUND:
From many calling locations, a V.34 connection is a successful connection for a V.90 modem.
ADDITIONAL INFORMATION:
Background
The majority of phone lines in North America will support V.90 connect speeds. However, there are some phone line configurations that will not allow V.90 connections and will cause the modem to drop back to V.34 rates. Industry estimates of lines not allowing V.90 connect rates, range from 5% to 20%. For connections through PBXÆs, typical for offices and hotels, these estimates are higher, 10%-30%.
The TP600 and TP770 V.90 modem supports connect speeds from 53kbps* down to 32kbps. Most telephone lines that support V.90 connections will support connections between 40kbps and 48kbps.
There are some phone line configurations that will cause difficulty for high speed V.90 connections. This is primarily due to line impairments. Line impairments are telephone network conditions that create difficulty for high speed modem connections. Line conditions and configurations can change, therefore lines that are not capable of high speed V.90 connections today, may be capable in the future.
Requirements for connection at V.90 speeds
Possible Causes
Things to try that could possibly help
Articles about V.90
http://www.zdnet.com:80/computershopper/edit/cshopper/content/9902/383154b.html
http://56k.com/cons/
http://www.v90.com
http://www.computers.com/reviews/comparative/substory/0,29,0-14-257672-667659-1,00.html?sr.co.crr.inav.crsu667659
Search Keywords |
| |
Document Category |
Communications | |
Date Created |
18-02-99 | |
Last Updated |
26-02-99 | |
Revision Date |
| |
Brand |
IBM ThinkPad | |
Product Family |
ThinkPad 600, ThinkPad 600E, ThinkPad 770, ThinkPad 770E/ED, ThinkPad 770X, ThinkPad 770Z | |
Machine Type |
2645, 2646, 9549, 9544 | |
Model |
Various | |
TypeModel |
| |
Retain Tip (if applicable) |
| |
Reverse Doclinks |