Netmotion VPN having loss of connection over GPRS Network

Here are the Facts:

We are using a VPN like connection provided by NetMotion. This application was created specifically for mobile applications. We have been dropping connection through netmotion VPN very frequently lately. Netmotion has done some testing, over various network connections. They seem to think that our GPRS network connection created the failure. Netmotion has suggested that "lag time" on the part of our network is most likely the issue.

There is No where on the Ericsson SGSN or the Ericsson GGSN where any latency related timer can be set/adjusted.

Other Facts:

Only one of three aps. are being effected.
The app has a 60 second keep-alive.
The NetMotion software flashes a yellow alarm when communication back to the server is lost.
The yellow alarms come in often at 1 to 2 second duration.
The yellow alarms sometimes last for 30 seconds or more

Q: Does anyone have a clue what we are working against here????

ANSWER: All the Frame relay links were looked at: They were both good on the Administrative state and the Operational sate. Gb Traces/Capture was taken using Acterna 8630 -- there were NO unusual level of RAU Failure network wide (Routing Area Update Failure) -- In fact there were NO RAU Failures for the cell sites in the area of the customer.

Bare in mind we are dealing with VPN of 3rd part over our GPRS/EDGE Network. Something every reader of this resolution should be aware of is the MTU value -- it has to be correctly set on the client's pc/laptop and also on the server -- A wrong/incorrect MTU can lead to loss of packets which in turn can reflect poor or degraded connectivity.

Wrong MTU value is the reason why my customer experienced the type of problem they had getting their NetMotion VPN to work. Once we were able to help them determine the Optimum MTU value -- things started working smoothly for them.

Thanks, Michael Folorunso

Dododawa wrote: