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Posts: 5 | Thanked: 0 times | Joined on Feb 2007 @ Kamloops, BC
#1
Has anyone noticed that SSH connections *to* their N800 from a remote machine are very slow? I've tried installing both the Dropbear and openssh servers on my N800, and in each case, at times I get appreciable lag (on the order of tens of seconds to minutes) between keypresses when I ssh to my N800.

This behavior began to exhibit itself after I installed the most recent N800 flash update. Prior to that, I was able to ssh/rsync without any trouble.

Any thoughts? Outgoing connections *from* the N800 (including outgoing SSH) seem just fine, so it's not a problem with the network in general.

- Mike
 
Posts: 23 | Thanked: 2 times | Joined on Jan 2007
#2
I have similar problems, not as severe. It usually only lags once in a while. And then it lags for a shorter period of time. It seems like it might have something to do with where the N800 is located in relation to the Wireless Router i have. If I move it when it is lagging it picks up and lags less. I have a few "sweet" spots where I can place it to minimize the lag.
 
Posts: 5 | Thanked: 0 times | Joined on Feb 2007 @ Kamloops, BC
#3
hrm. I don't think that's the problem here as I'm literally sitting beside my router. Besides, outgoing connections are just fine, including outgoing SSH. It's just on incoming SSH connections to the sshd daemon that I see the problem.

Very odd.
 
Posts: 17 | Thanked: 13 times | Joined on Jan 2007 @ Cupertino, CA
#4
Hmm, sometimes problems like this are DNS related... A server tries to map your IP address to a name, but doesn't get a result for a long time (or just times out and gives up).

You could sniff the traffic to verify. Or, since I assume the Nokia is using /etc/hosts, add a temporary entry there for your other system to see if that fixes the delay.
 

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Posts: 5 | Thanked: 0 times | Joined on Feb 2007 @ Kamloops, BC
#5
Thanks, but it's not DNS either. DNS is used to resolve the initial IP to connect to which is happening ok. Name resolution ends once the IP is discovered and a connection is made. There just seems to be an odd lag while the connection is active.

Checking the load average on the N800 doesn't show anything out of the ordinary, and as I said - outgoing connections from the N800 are great. So it's not overall network trouble. It really seems like a local application problem with sshd, but for the life of me I can't figure out why.

Back to the drawing board...
 
Posts: 5 | Thanked: 0 times | Joined on Feb 2007 @ Kamloops, BC
#6
Another odd symptom that I just noticed tonight:

If I open up an xterminal on the N800 and ssh *out* to another machine (Computer 1), then ssh back *in* from a different box (Computer 2), as follows:

Computer 1 <----- N800 <----- Computer 2

The connection between Computer 2 and the N800 lags as before. The outgoing SSH connection from the N800 to Computer 1 is fine.

Now here's the odd part: if the Comp2 -> N800 connection lags, all I need to do is type a few characters into the N800 ---> Computer 1 ssh session and everything de-lags itself.

It's almost as though the unit is going into some sort of low-activity power-saving mode... only I've checked and my WLAN inactivity timeout is set to unlimited.

Very odd.
 
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Posts: 2,853 | Thanked: 968 times | Joined on Nov 2005
#7
It's power-saving all right. I had something similar on my 770 under OS2005 : I could not usefully ssh from the PC to the tablet because battery management would kick in during pauses and the Wifi would go into a sort of "sleep mode", although still connected. Incoming data would not wake it up, only outgoing traffic from the tablet itself would.

Others has the same symptom, but strangely enough with varying degrees of gravity - from mere annoyance to unusable (in my case).
Some solved the problem by streaming music or other stuff to the tablet to keep the Wifi alive during the ssh session. Through trial and error I found than opening an xterm and pinging an external host every 4 seconds was enough. But not every 5 seconds :-)
 
Posts: 70 | Thanked: 16 times | Joined on Jan 2006 @ Nantes (France)
#8
Originally Posted by fpp View Post
It's power-saving all right. I had something similar on my 770 under OS2005 : I could not usefully ssh from the PC to the tablet because battery management would kick in during pauses and the Wifi would go into a sort of "sleep mode", although still connected. Incoming data would not wake it up, only outgoing traffic from the tablet itself would.
I've noticed this on my N800 and I had the same problem with my Nokia 770. Your explanations make sense, I think...
 
Posts: 17 | Thanked: 13 times | Joined on Jan 2007 @ Cupertino, CA
#9
Originally Posted by mkelly View Post
Thanks, but it's not DNS either. DNS is used to resolve the initial IP to connect to which is happening ok. Name resolution ends once the IP is discovered and a connection is made.
The problem I was referring to happens on the *server* side. For example, after you connect the server might want to log a message like "connection from host.foo.com". But the reverse lookup on the client's IP is slow, and causes things to stall until it completes or times out.

But it sounds now like that's not the problem you're having anyway. :-)
 
Posts: 51 | Thanked: 2 times | Joined on Nov 2005
#10
Can someone please provide instructions for installing opensh on N800?
 
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