Receiving concatenated messages with Siemens M20

Receiving concatenated messages with Siemens M20 SearchSearch
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Bob Gilchrist
New member
Username: Dtl

Post Number: 1
Registered: 06-2004
Posted on Tuesday, June 15, 2004 - 08:46 pm:   

We have setup the NOW gateway using a Siemens M20 GSM modem, serially-attached to a Win2K server. The gateway sends and receives just fine. It also sends concatenated messages. However, it seems unable to receive concatenated messages - they get interpreted as binary data and do not arrive. Anyone know if this is a limitation of the M20 modem? And if there is a firmware upgrade available for the M20 that might fix this? And if not, can anyone confirm that the Siemens M35 DOES have this capability? Thanks! (*We've got three M20's here and I'm anxious to use them if we can!)
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 2841
Registered: 10-2002
Posted on Tuesday, June 15, 2004 - 10:01 pm:   

Hi Bob,

I'd like to see a debug log to see what the situation is with these messages.

To enable the debug log, manually edit SMSGW.INI, and under the [SMSGW] section header, add Debug=Yes. Then restart the NowSMS service. Send in another group of these concatenated messages.

Then post the SMSDEBUG.LOG details here, so that we can analyse what is occurring.

I've not seen any problems on the Siemens MC35T. But I'd be really surprised if the M20 had a problem in this area ... usually problems in handling of multipart messages are with phone modems, because the phone tries to do some processing of the message before routing it over the modem interface. However, dedicated modem devices are generally transparent, and just pass the message along as it was received.

-bn
Bob Gilchrist
New member
Username: Dtl

Post Number: 2
Registered: 06-2004
Posted on Wednesday, June 16, 2004 - 10:39 am:   

Thanks!

debug log attached. Apologies if this is a duplicate post - I'm not feeling to bright this morning!

Bob
application/octet-streamSMS debug log
smsdebug.log (3.0 k)
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 2852
Registered: 10-2002
Posted on Wednesday, June 16, 2004 - 07:41 pm:   

Bob,

Is that typical of what you see?

Whenver a multiple part message is sent to the modem, do you only see the first part?

Basically, what's happening in the log is that NowSMS is only receiving the first part of a three part message. So we're waiting for the other two parts to be received, so the message can be re-assembled.

What's not clear is why the other parts are not being received.

I've never used the M20, so I don't know if there would be an issue with it, but it would surprise me if there was. I do recall that if you try to use the Ericsson R380 as a GSM modem, it does something like this with multipart messages. But I've never seen it with an actual modem device.

Can you try some more and post another SMSDEBUG.LOG? I'm just wondering if the case is that you always only receive the first part of the multipart message.

-bn
Bob Gilchrist
New member
Username: Dtl

Post Number: 3
Registered: 06-2004
Posted on Wednesday, June 16, 2004 - 11:39 pm:   

Bryce

Thanks - but actually, nothing is apparently received at all by the client to the gateway. I have now heard that the M20 is incapable of receiving multi-part messages - this was a response from "Bob" at TLC - though it has to be said that their interest is in selling the current (M35) product.. If you still think it worthwhile to send more debug stuff, I will..

Best
Bob
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 2871
Registered: 10-2002
Posted on Thursday, June 17, 2004 - 08:54 pm:   

Bob,

Right, the gateway won't forward the message to the client until it has received the entire message.

It is receiving an indicator that the first of three parts has arrived, so it is waiting for the other two parts.

As I don't have any direct experience with the M20, it is certainly possible that the device was incapable of receiving multi-part messages. That seems odd to me, but possible. (Like I said, I have observed this exact same behaviour with an Ericsson R380 in use as a GSM modem, so I have seen this before.)

These partial messages are likely queued in your SMS-IN directory, where you will see file names like this:

phonenumber-XX-X-1.SAR

Do you see any of these messages where the last "-1" shows a different numeric value? If not, then it suggests that the modem is having a consistent problem receiving multipart messages, and is only passing along the first part.

-bn
Bob Gilchrist
New member
Username: Dtl

Post Number: 4
Registered: 06-2004
Posted on Saturday, June 19, 2004 - 12:06 pm:   

Thanks B
No, there was just the -1. So I bought a M35i terminal. I deinstalled the old modem and reinstall the windows .inf file for the M35. I have done a few tests and it sends - and received - single and multipart msgs, BUT the sent messages appear to get truncated to four in number. Is that an intrinsic limitation of SMS (i.e. a max of four concatenated msgs?) or might I have a problem?
Thanks for your assistance on this. Bob
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 2891
Registered: 10-2002
Posted on Tuesday, June 22, 2004 - 08:24 pm:   

Bob,

No, 4 concatenated messages is not an intrinsic limit. Although some handsets do have fixed limits in the 3 to 5 part range.

-bn
mairy
Unregistered guest
Posted on Sunday, July 11, 2004 - 08:54 am:   

We have GSM modem . we nead to now how to send concatenated messages . we nead more information about this }}
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 3036
Registered: 10-2002
Posted on Wednesday, July 14, 2004 - 03:34 pm:   

Hi Mairy,

NowSMS handles concatenated messages automatically.

-bn