Hello,
I am struggling to get TCPnet's PPP to work reliably with my GPRS modem.
In low traffic situations everything seems fine -- I am able to get the modem online, open sockets, accept incoming sockets, exchange data, etc. However, when I add on my SSL application, things die during the SSL negotiation. By enabling the PPP debug output I can see that packets are being sent out the PPP interface, but that packets stop coming back in before the negotiation is completed. Eventually the TCP Socket hits its maximum number of retries and fails out.
Now, the interesting thing is that if I try to do the exact same thing through the Ethernet interface (swapping out GPRS/PPP for Ethernet) everything works great.
The only errors I see coming out of the PPP debug are as follows:
On initialization: "PPP ERR: LCP Magic Number Option Rejected." Occasionally, during the failed SSL negotiation: "PPP: *** Processing PPP frame *** PPP ERR: Frame FCS Check Failed"
I am suspicious that this might be an issue with the time out and retry settings of the PPP and TCP socket interface. Could anybody who has used this with a GPRS/GSM modem give me some pointers?
Any thoughts you might have would be greatly appreciated! Thanks.