cyanarnofsky
Posts: 70
Joined: Tue Jul 31, 2012 11:33 pm

3G Modem Speeds

Tue Jul 01, 2014 11:46 pm

Hey just curious if there is any Wvdial/PPP knowledgeable people about. I am curious if it is simply a Pi constraint or if I am missing a bottleneck that's killing this connection. Connects great, even have a monitor script that watches connection, if PPP is down it checks RSSI or signal strength, once a acceptable signal is reached wvdial redials. Works great for keeping the connection constant, but my speed is awful.

I have the baud rate set consistent at 115200 through all my configs, which should get me near 1MB/sec and I get like 32-64KB/sec usually. Possible I am missing a setting or an adjustment that could get this going at a more consistent speed?

cyanarnofsky
Posts: 70
Joined: Tue Jul 31, 2012 11:33 pm

Re: 3G Modem Speeds

Wed Jul 02, 2014 3:33 pm

Possible USB serial speeds are not adjusted to handle higher bauds?

User avatar
topguy
Posts: 6288
Joined: Tue Oct 09, 2012 11:46 am
Location: Trondheim, Norway

Re: 3G Modem Speeds

Wed Jul 02, 2014 4:45 pm

cyanarnofsky wrote: I have the baud rate set consistent at 115200 through all my configs, which should get me near 1MB/sec and I get like 32-64KB/sec usually.
Actually a baudrate of 115200 should give you max. 14,4 KB a second. But I'm guessing the modem is an USB device so it might not really have any relevance what the baudrate is. But you can always test with 230400 and 460800 and see if it has an effect.

I know ppp but not wvdial. Do you have a log of the handshaking between pppd and the modem ? The usual procedure is to initiate data with "atdt *99*" (or some variant) and the modem answers with "CONNECT xxxx" where xxxx equals the connection speed. I've seen "connect 7200000" on some 3G modems, but that doesnt mean you will get 7,2 Mbps.

cyanarnofsky
Posts: 70
Joined: Tue Jul 31, 2012 11:33 pm

Re: 3G Modem Speeds

Mon Jul 14, 2014 6:31 pm

I was a bit off then, I ran through some recent updates for the Pi and it seems to actually have increased now. Makes things simple. :). I also used UseDNS No command to improve login prompt times for SSH itself. Between those 2 I am in acceptable range for sure now.

I actually get

Connect 3100000

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