Panasonic GD87 / GPRS

[_JJ_]

Has anyone managed to use a Vodafone Live! Panasonic GD87 with their Psion yet? I am having mixed results...

Transferring pictures and Agenda entries via infrared works fine, both to and from the phone. Making a CSD connection to the Internet also works fine (using the Vodafone 900884 dial-up number), but I cannot connect using GPRS.

I am using the usual AT+CGDCONT=1,"IP","internet" command to set up the PDP context, with a dial-up number of *99***1#. The display on the phone shows that it is connecting, and the data counter clocks up as I check email, view web pages, etc. But not a great deal happens on the Psion side! Opera can resolve IP addresses, but then hangs on 'Sending request to ...'. I can download headers with POP3 email, but not the messages themselves?! I can ping the default gateway, but nothing else! Most bizarre!

I have used Rudolf Konig's route.exe program to show that I have been allocated an IP address, and that the Psion has found the DNS server.
AT+CGDCONT? shows that CID 1 is the only PDP context in the phone. The alternative dial-up number (*99#) to select the default PDP context does not even connect.

I know that it's not a problem with my Vodafone account, because I can connect perfectly using the same SIM card in my Ericsson T39m. In the same way this proves that my 7book is not faulty (but I've done a soft reset anyway).

Any help would be greatly appreciated.


Regards,

JJ :confused:

[diem]

Well, I've not used that phone, but the logic of what you've done does suggest a problem with the phone. Either it needs some additional AT commands or, perhaps, a firmware upgrade.

I'd see what Vodafone know about it, and if not them then maybe Panasonic?

[MikeMcC]

Just a thought but have you installed Psion's "Mobile GPRS Update" in the '7Book'? There is a copy on the Series 5 page of my website if you want to give that a try.

Otherwise, you seem to have everything set up properly and, as it works with the Ericsson phone, it seems that the problem may lie with the Panasonic phone.

[_JJ_]

Thanks for the replies. I've just tried installing the "Mobile GPRS Update" as you suggest Mike, but this has the effect of completely breaking IR comms - it does not even get as far as dialing the number. The same goes for the "Mobile Connectivity Update".

However I did notice that the connection does work if I force a small IP packet size, e.g. by opening a telnet session from the 7Book (each keypress will be sent in a separate [small] packet). Simple UNIX commands which don't return much output (e.g. typing 'pwd') work fine, but anything that would create larger IP packets (e.g. reading a text file) causes the connection to hang. This is in keeping with my earlier observation that DNS lookups and fetching email headers work, but downloading web pages or emails does not.

So it seems that this could be a problem with the MTU or MRU sizes used in the PPP connection between the Psion and the phone. Does anyone know how to find out what MTU the Psion is using, and how to change it?


Cheers,

JJ

[netBookBabe]

Originally posted by _JJ_
I've just tried installing the "Mobile GPRS Update" as you suggest Mike, but this has the effect of completely breaking IR comms ...GPRS update for some reason seems to disable the IR port - I found it necessary to delete the file C:\System\libs\irda.prt, then everything worked fine!

Julie

[_JJ_]

Thanks for the tip Julie - deleting the irda.prt file did re-enable the IR port. Unfortunately the update didn't cure the connection problem though.

I've done some more testing and I think (?!) I may have worked it out.

The Panasonic GD87 does not have the most complete PPP implementation - it does not escape control characters properly, there are also problems obtaining a remote IP address from the phone with the Linux pppd daemon. But what I did notice is that if the client requests an MRU less than 1500, the ppp daemon in the phone does not acknowledge the request and tells the client that it will still use 1500. An extract from the log file is shown below:

&nbsp;&nbsp;&nbsp;&nbsp;sent [LCP ConfReq id=0x2 <mru 576> <asyncmap 0x0> <magic 0xa4963a9a>]
&nbsp;&nbsp;&nbsp;&nbsp;rcvd [LCP ConfNak id=0x2 <mru 1500>]

In comparison, the Ericsson T39m does accept different MRU values:

&nbsp;&nbsp;&nbsp;&nbsp;sent [LCP ConfReq id=0x2 <mru 576> <asyncmap 0x0> <pcomp> <accomp>]
&nbsp;&nbsp;&nbsp;&nbsp;rcvd [LCP ConfAck id=0x2 <mru 576> <asyncmap 0x0> <pcomp> <accomp>]

So my theory (but this is as yet untested) is that the Psion requests an MRU of 576, the phone tells the Psion to use an MRU of 1500, both devices ignore each other's requests and go their own way. The result is that any packets larger that 576 bytes will be dropped.

Hmph.


JJ

[jolivares]

I have the same problem with my Psion 5MX and GD87. However, GD87 connects without no problem to internet via GPRS using my Toshiba notebook.

So, the problem is not the phone but Psion.

[MikeMcC]

So, the problem is not the phone but Psion I don't believe the problem is that simple because, so far, the GD87 is the only GPRS phone I have heard of which seems to have a compatibility problem when trying to use GPRS with a Psion. I understand a normal GSM connection with the GD87 works OK.

Comparison with your Toshiba notebook is not really significant because a PC can use any modem drivers/software which may be necessary, but the Psion cannot.

I have a Nokia phone which works with GPRS and my Revo, 5mx, Toshiba notebook (Win 98SE) and desktop PC (Win XP), so the Psion is quite capable of running a GPRS connection with a phone which adheres to the conventional protocols - the GD87 may not do this.

[jolivares]

I don't think so. I used generic modem in my Toshiba (not panasonic specific driver) without any initialization string and works fine, at same speed of Ericsson T39m.

If Psion developed a conectivity update for some phones that was because Psion wasn't compatible with them, so the problem is in the Psion side, no ?

[MikeMcC]

I used generic modem in my Toshiba (not panasonic specific driver) without any initialization string and works fine, OK, but I don't know how you established a GPRS connection using a generic modem driver and no initialisation string. :confused:
If Psion developed a conectivity update for some phones that was because Psion wasn't compatible with them, so the problem is in the Psion side, no ? There are two updates - the original "Mobile Connectivity Update" which updated the IR drivers and was required for most IR phones and also the IR Travel Modem, with the 5mx and MC218 only. There is now a second update - the "Mobile GPRS Update" which, as far as I am aware, is required for all GPRS connections, that is for all phones and for all models of Psion/MC218/Mako.

[jolivares]

Mike:

To stablish a connection I just dial *99***2#. The definitions are on my phone, so I don't need to use the initialisation string. And it works fine!

About the updates, I use the version 2.0 (from your site, I guess) because with 1.10, the GD87 didn't worked.
The question is: if Psion need updates to work with some phones maybe now needs another to "understand" this new model.

Panasonic here in Portugal told me that the GD87 works with all notebooks (and they're right), so the problem need to be solved by Psion. Psion told me that is a phone problem. I'm just trying to identify the problem to solve it.

Thank's for your cooperation, Mike

[janine]

i always try to connect to internet, but the message is always says connection failed. how can i set the connection to my phone?