Problems With 24/7 Uptime

[Amanda_Newton]

Greetings,

Our company has decides to use Vodafone products for a certain project that we are conducting.
In a nutshell we have 10 computers, each connected to the Vodafone wireless network which are running 24 hours a day.

Data transfer is mandatory, so we have checked "3G only".

During are 3 months testing period we got these results:
- connection can sometimes break for a very short period of time, couple of seconds. But it doesn't effect the data transfer.
- sometimes connection to 3G gets completely lost and does not come back.
Steps we take in solving this:
1. try to restart Vodafone Mobile Lite and wait for connection
2. restart the computer and try again

In some 98% percent steps 1 and 2 are indeed sufficient, but here comes the real problem..
Sometimes the connection simply breaks and doesn't come back even after computer restart.
Unplugging and plugging back the USB modem also doesn't help.

After the restart modem keeps flashing green light - which means that it is trying to connect, but it just stays in that state.
To describe in more details - the state that occurs is the identical as to when the bills were not paid in full. Vodafone just refuses to make a connection and keeps blinking the green light.

The only solution to this is a complete reinstall of Mobile device. This can really be difficult, especially as our computers are placed in a distant locations and we rely on automated processes.

Could you please give us some information as to why such situations occur and why?
If we knew why this happens perhaps are tech department could come up with a workaround.
As stated before, these ARE rare, but do bring our complete system to a halt. As we only connect to these remote machines via VNC software, when such failure happens we must send teams to inspect the physical location.
We experience these problems perhaps once in 30-40 days on constant connection (with only mild disturbances other then that).

Can this be somehow related to the operating system (Windows XP) ?
Is cache data stored up to the point where it messes up the modem?
Could this be prevented with periodical deletion of temp files or perhaps disconecting and recconecting mobile connection every 48 hours or so?

This problem is not single user specific as we experienced it on several machines of which some also had different processors etc. But all were windows XP.

We noticed that Vodafone created several directories on install, which ones should we remove and what steps to take besides regular uninstall in order to make a full clean install?

Can we contact our provider's support center regarding specific issues and what should we tell them? Person as the support center told us to open the Vodafone software, which we could not as our computers are elsewhere. We do check the connection and connect directly to these computers (if they are online) via corporate VNC software and are alerted if a connection is down.
Can a person from support center help us in any way without us traveling to the phisical location of the device? As to check the device by providing him/her our serial number?

Thank you in advance and please ask for more details if needed.

Sincerely, Amanda N.

[cjm1979]

Greetings,

Our company has decides to use Vodafone products for a certain project that we are conducting.
In a nutshell we have 10 computers, each connected to the Vodafone wireless network which are running 24 hours a day.

Data transfer is mandatory, so we have checked "3G only".

During are 3 months testing period we got these results:
- connection can sometimes break for a very short period of time, couple of seconds. But it doesn't effect the data transfer.
- sometimes connection to 3G gets completely lost and does not come back.
Steps we take in solving this:
1. try to restart Vodafone Mobile Lite and wait for connection
2. restart the computer and try again

In some 98% percent steps 1 and 2 are indeed sufficient, but here comes the real problem..
Sometimes the connection simply breaks and doesn't come back even after computer restart.
Unplugging and plugging back the USB modem also doesn't help.

After the restart modem keeps flashing green light - which means that it is trying to connect, but it just stays in that state.
To describe in more details - the state that occurs is the identical as to when the bills were not paid in full. Vodafone just refuses to make a connection and keeps blinking the green light.

The only solution to this is a complete reinstall of Mobile device. This can really be difficult, especially as our computers are placed in a distant locations and we rely on automated processes.

Could you please give us some information as to why such situations occur and why?
If we knew why this happens perhaps are tech department could come up with a workaround.
As stated before, these ARE rare, but do bring our complete system to a halt. As we only connect to these remote machines via VNC software, when such failure happens we must send teams to inspect the physical location.
We experience these problems perhaps once in 30-40 days on constant connection (with only mild disturbances other then that).

Can this be somehow related to the operating system (Windows XP) ?
Is cache data stored up to the point where it messes up the modem?
Could this be prevented with periodical deletion of temp files or perhaps disconecting and recconecting mobile connection every 48 hours or so?

This problem is not single user specific as we experienced it on several machines of which some also had different processors etc. But all were windows XP.

We noticed that Vodafone created several directories on install, which ones should we remove and what steps to take besides regular uninstall in order to make a full clean install?

Can we contact our provider's support center regarding specific issues and what should we tell them? Person as the support center told us to open the Vodafone software, which we could not as our computers are elsewhere. We do check the connection and connect directly to these computers (if they are online) via corporate VNC software and are alerted if a connection is down.
Can a person from support center help us in any way without us traveling to the phisical location of the device? As to check the device by providing him/her our serial number?

Thank you in advance and please ask for more details if needed.

Sincerely, Amanda N.

Have you checked your postcode for coverage of 3.5G? It could be at a busy time that it cant get 3G. If the 3.5G signal was really good where you are and you selected 3G prefered it would pick 3.5G most of the time but drop down to 3G and then gprs if it was struggleing.

[Retired-Jon_V]

Hi Amanda,

Thanks for your post

From the description of your problem, it sounds to me like this is a SIM card registration issue. The root cause of this issue is most likely the constant active connection. SIM cards and the mobile network in general, were not designed to hold an "Always-On" connection, and generally need to be re-registered on the network once every 24 hours in order to maintain a stable connection.

A quick fix for when this issue happens, would be to use the VMC software to "manually roam" onto another network, and then back onto Vodafone again. You'll find this option under Tools > Select Network.

You can also remove the SIM from the device, and place it into a mobile phone to do this, if that is easier.

As a long term resolution to this kind of problem, you can try having the devices automatically disconnect/reconnect to the internet every 24 hours, however this may not be sufficient - as it usually takes a full power-cycle on the modem itself to trigger a new network registration. A daily reboot or manual roam might yeild better results.

Jon

eForum Team

[heady]

Greetings,

Our company has decides to use Vodafone products for a certain project that we are conducting.
In a nutshell we have 10 computers, each connected to the Vodafone wireless network which are running 24 hours a day.

Data transfer is mandatory, so we have checked "3G only".

The question I have is what are the characteristics of the data transfer? Are these remote SCADA or sensor systems dribbling back status and measurements or is the data transfer fully interactive HDTV?

The reason I ask is that if the data transfer is the former - then standard GSM GPRS or slow 3G would in most cases I've experienced be good enough. Whereas; for the later - then 3.5G would have difficulties to cope in all environmental situations. If the bandwidth of standard GSM GPRS is good enough for your purpose then I'd expect it to be the more stable and predictable from an air interface point of view.

However, reading below - it may not be your problem.

During are 3 months testing period we got these results:
- connection can sometimes break for a very short period of time, couple of seconds. But it doesn't effect the data transfer.
- sometimes connection to 3G gets completely lost and does not come back.
Steps we take in solving this:
1. try to restart Vodafone Mobile Lite and wait for connection
2. restart the computer and try again

In some 98% percent steps 1 and 2 are indeed sufficient, but here comes the real problem..
Sometimes the connection simply breaks and doesn't come back even after computer restart.
Unplugging and plugging back the USB modem also doesn't help.

After the restart modem keeps flashing green light - which means that it is trying to connect, but it just stays in that state.
To describe in more details - the state that occurs is the identical as to when the bills were not paid in full. Vodafone just refuses to make a connection and keeps blinking the green light.

The only solution to this is a complete reinstall of Mobile device. This can really be difficult, especially as our computers are placed in a distant locations and we rely on automated processes.

Could you please give us some information as to why such situations occur and why?
If we knew why this happens perhaps are tech department could come up with a workaround.
As stated before, these ARE rare, but do bring our complete system to a halt. As we only connect to these remote machines via VNC software, when such failure happens we must send teams to inspect the physical location.
We experience these problems perhaps once in 30-40 days on constant connection (with only mild disturbances other then that).

Can this be somehow related to the operating system (Windows XP) ?

I would definitely say this problem as described has something to do with Windows XP and associated software.

I had the misfortune recently of using another operators Mobile Broadband solution (not Vodafone's) on a WindowsXP Laptop and the application that provided the GUI as well as the usage monitor etc... leaked memory like a sieve. This meant that after 3/4 of a day of usage everything on the Laptop would start to fail in unexpected ways. This would create a snowball effect of errors until the only option was to reboot.

The solution was either reboot every 2hrs or not use the bundled software and use the standard Windows dial-up modem connection instead.

I'm not saying that this is specifically your problem - but it would be worth a look.

Is cache data stored up to the point where it messes up the modem?
Could this be prevented with periodical deletion of temp files or perhaps disconecting and recconecting mobile connection every 48 hours or so?

This problem is not single user specific as we experienced it on several machines of which some also had different processors etc. But all were windows XP.

We noticed that Vodafone created several directories on install, which ones should we remove and what steps to take besides regular uninstall in order to make a full clean install?

Can we contact our provider's support center regarding specific issues and what should we tell them? Person as the support center told us to open the Vodafone software, which we could not as our computers are elsewhere. We do check the connection and connect directly to these computers (if they are online) via corporate VNC software and are alerted if a connection is down.
Can a person from support center help us in any way without us traveling to the phisical location of the device? As to check the device by providing him/her our serial number?

The exchange equipment would be able to tell Vodafone technicians when the modem last connected; as well as its current state; statistics; and even page the modem; and initiate connections from the network. However, I'm not sure what/which of these maintenance features have been exposed to the Vodafone support staff or whether the Vodafone Mobile Broadband modem control software would support network initiated connections. So I'm not sure how useful any of this would be for your situation.

Thank you in advance and please ask for more details if needed.

Sincerely, Amanda N.

Now I'm definitely not a Microsoft Windows person - I only put up with it on the locked-down work machine - so I won't be able to help specifically in your case. But I can tell you what I've done.

I've got a test bed I play with that is connected via Vodafone Mobile Broadband and despite the little issues I'm currently having; have been reasonably happy with the consistency of the service. The test bed consists of mostly Linux and OpenSolaris machines with a token Windows2k3 server and a couple of WindowsXP Laptops.

I have a Huawei E220 modem connected to one of the Linux machines which provides the external link.

At least once a day the Vodafone BRAS/GGSN node sends a PPP LCP TermReq command to the device terminating the PPP session (WindowsXP mobile broadband modem control software in your case). This "hangs up" the modem. i.e.:
May 18 14:58:44 ... pppd[23725]: rcvd [LCP TermReq id=0xa9]
May 18 14:58:44 ... pppd[23725]: LCP terminated by peer
May 18 14:58:44 ... pppd[23725]: Connect time 1309.8 minutes.
May 18 14:58:44 ... pppd[23725]: Sent 13180513 bytes, received 66637571 bytes.
...
May 18 14:58:44 ... pppd[23725]: sent [LCP TermAck id=0xa9]
...
May 18 14:58:47 ... pppd[23725]: Connection terminated.
May 18 14:58:48 ... pppd[23725]: Modem hangup
Note: for me - this use to happen like clockwork around 22:00 everyday; however, recently the timing has been random.

It is then up to the device terminating the PPP session (WindowsXP mobile broadband modem control software in your case) to reinitialise the link and re-establish the PPP link back through to the BRAS/GGSN node; therefore, allowing Internet connectivity.

Note that this PPP LCP TermReq is independent of the situation Jon_Vodefone describes which is called a "routing area update" which should not affect service. The "routing area update" occurs when a modem registers to the network, when a modem crosses mobile routing areas or via a timer - all situations are controlled by Vodafone. The GPRS network was designed to provide an "always-on" data link when on the move or stationary. The procedure Jon_Vodafone describes is what needs to be done when the modem doesn't deal with these updates properly.

The timeframe of this PPP LCP TermReq is independent of the "routing area updates" and is set by Vodafone or the equipment manufacturer. The idea is to knock-off the top talkers; however, it doesn't require the IQ of a rocket scientist to work out how to configure the software to auto-dial upon hang-up.

Most software will auto-dial upon hang-up; if configured to do so.

The next issue is the modems.

I specifically choose the Huawei E220 after much research. With the decision based upon reports of stability when used on UNIX type systems; the fact that it is an intelligent modem not a software modem, as well as the fact that it followed the 3GPP AT command standard fairly closely and therefore, could be controlled via a simple serial terminal using well known commands. There was no need for special modem control software. From what I've researched this is not always true of other modem models.

The issue; however, is that not all consumer devices are stable - and the E220 is no exception - it will hang from time to time.

The solution that I'm crafting to try to have an always available connection checks to see if there is IP connectivity to external Internet server(s). If not it will check if the modem is responding on the tertiary control channel; if so it will terminate the PPP session and attempt to re-establish the PPP session. It will effectively continue this forever until a link is established.

If the modem is not responding on the tertiary control channel; it will unload the kernel modules that control the USB bus, serial drivers, PPP drivers etc... It will then reset the USB bus manually and then reload the associated kernel modules. This does the same thing as "pulling and pushing" the modem. This will repeat until the modem responds to the tertiary control channel. Whereby, it will then attempt to re-establish the PPP session and will continue forever until a link is established.

I don't have this fully automated yet - but so far - I've not had to - I have not had any problems establishing a PPP session using my base scripts.

My issues occur usually during normal operation. If I terminate the PPP session and re-establish then usually my issue is mitigated for a little while. However, at the moment I have not been able to find suitable triggers to measure to kick off this process.

Windows now has scripting support; therefore, talk to your techy's to develop a similar system like that above.