|
Dial Up Network Tips |
Completely Revised 24-October-99
These tips are based on my own empirical tests and apply only to Windows 98.
Windows 98 is more or less the same as Windows 95 with winsock 2 and DUN 1.3. There is not too much to do to improve it. The main area that need attention is the receive window which defaults to 8192 and means windows is a bit slow in acknowledging data received.
Also see the FAQ for answers to common questions. For Windows 95 see the Windows 95 DUN tips page.
To save repeating myself I refer below to Your Dun Properties by that I mean:- Double click My Computer, Double Click Dial-Up Networking, Right click your ISP DUN and select properties.
 |
||||||||
| 1 | Open control panel and double click Network. Select Configuration
tab / Dial-Up Adapter and click Properties button. Select Advanced tab and
set IPX header compression to yes and record a log file to no. Click all
the OKs. Optionally you can change MaxMTU (packet size)here from the default
of auto (=small on DUN) to small (576), medium (1000), or large(1500). The
FAQ lists the method for determining the MaxMTU. |
|
||||||
| 2 | Open Regedit (back up registry first) and expand HKEY_LOCAL_MACHINE key. Find System\CurrentControlSet\Services\VxD\MSTCP. Add a new dword entry with right click and set the name to DefaultRcvWindow and set its value to (MaxMTU-40)x4. So for 576 the value is 2144 (decimal). |
|
||||||
| 3 | Turn off MNP5 compression. On USR modems this is usually
&K3. On zoom I am told it is %C2. You can either add this as an extra
setting in Your DUN Properties, General Tab, Configure Button, Connection
Tab, Advanced Button. Or use RegEdit to change all occurrences in the registry
from &K1 to &K3. |
|
||||||
| 4 | Go to Your DUN Properties, General Tab, Configure Button,
Connection Tab, Advanced Button. Tick 'Use error control', 'compress data',
'Use flow control' and select 'Hardware' flow control. Untick record a log
file. Click OK until you are back to the first window. Select the sever
types tab. Untick everything except TCP/IP protocol (unless your ISP requires
different). Click TCP/IP settings and tick IP header compression (the rest
your ISP should define). Click all the OKs. If you have an external modem
make sure the port speed is set to maximum. |
|
||||||
| 5 | Open Regedit (back up registry first) and expand HKEY_LOCAL_MACHINE key. Find System\CurrentControlSet\Services\VxD\NWLink\Ndi\params\cachesize and set the default value to 16. |
|
|
What has this all done? |
Only ticking TCP/IP protocol means time at logon isn't wasted trying the other protocols. The same goes for logon to network, you don't waste time trying to do it. The other ticks enable the modem internal compression and disable software compression. I find this the best with my ISP but other people claim that the reverse is better as the PC can have a larger dictionary. I found software compression worse but try it, you may get different results. The one thing in favour of software compression is that it takes some load off the serial port.
Not recording a log file also saves some overhead (disk activity) and I found it gave a slight improvement, some people claim it makes no difference but if you aren't having problems you don't need it so there is no harm in disabling it, which also saves some disk space. Similar arguments apply to disabling the ppplog.txt but the choice is yours.
All of this is a bit of suck it and see and it may not all work for you. It takes a lot of fiddling and testing to get optimum. At the moment my peak speeds (as reported by IE5) are arount 4.5kbytes/s when download zip files.
I am told that the crc in the modem data takes 4.97% so the maximum zip rate should be 0.9503x33600/8000=3.99k/s. at 33600 bps and of course proportionally high with the higher V90 speeds. I tend to get around the 40000 depending on the weather so I would seem to be pretty much foot to the floor. I don't think there is much else I can do (but if you know different drop me an email).
If you still have problems try ticking record a ppp log file (ppplog.txt in \windows) or a modem log file (modemlog.txt in \windows) and see if these reveal anything (the places to tick are listed above). Additionally you could try typing ati6 or ati11 in Hyper Terminal after you log off. Note, these are for USR modems, see your manual if these don't work for you. This should display diagnostics on the last call. If it says the last call was zero time then the modem init string in the registry is ATZ which is clearing the data the Navas Modem FAQ has the details about how to change this and lots of other stuff, including details of what the results of ati6 and ati11 mean.
Recently I have also found the 56k Modem Troubleshooting page which I think is better.
| Full Circuit Ltd - for all your electronics | {Home: | www.fullcircuit.com} | |
| designer / engineer / consultant needs | {Email: | mreeves@fullcircuit.com} |
