Slow Ipod wifi on lan

debitcardmayhem

GunJack wrote: »

^^^ that's the most constructive comment so far....any router having to work a mixed protocol will not perform optimally, and in some cases can even lead to devices on one of the protocols not being serviced properly and can cause poor responses and even dropouts. Practical example:- xbox on 11g, laptop on 11b, when the laptop wifi was in use it caused the xbox wifi to lag, drop connection, etc....changed laptop for 11g, locked router to 11g, no probs for xbox when new laptop in use

Why thank you GJ :cool:

GunJack

'salright mate, it was talking sense. I quoted the practical example to illustrate your point. I think that, plus the lack of processing & data handling capacity of the ipods, will probably be the bulk, if not all, the causes of the issue....

Big_Ed

The first ping seems to be the problem (maybe the ipod is coming out of some kind of sleep mode?). Anyway the other pings appear to be "normal". I just tried pinging my iphone from my laptop (wireless) and am getting similar times to you (apart from the first one).

debitcardmayhem

I know nothing about ipods but your problem also may be related to the MTU setting on your router/pc (But in all honesty it will be the setting on the ipods and I can't find much out about changing them and what I could involves Jailbreaking) , If you are running the pings from windows on your pc try this command increasing/decreasing the -l value until you don't see the "Packet needs to be fragmented but DF set." I would start at 1500 and then add/subtract 20 until you get a change to pings received, then change by 2 until you get the message again. eg

C:\Users\rob>ping -f -n 1 -l 1500 192.168.2.1

Pinging 192.168.2.1 with 1500 bytes of data:
Packet needs to be fragmented but DF set.

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\rob>ping -f -n 1 -l 1480 192.168.2.1

Pinging 192.168.2.1 with 1480 bytes of data:
Packet needs to be fragmented but DF set.

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

C:\Users\rob>ping -f -n 1 -l 1460 192.168.2.1

Pinging 192.168.2.1 with 1460 bytes of data:
Reply from 192.168.2.1: bytes=1460 time=2ms TTL=64

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 2ms, Maximum = 2ms, Average = 2ms

C:\Users\rob>ping -f -n 1 -l 1462 192.168.2.1

Pinging 192.168.2.1 with 1462 bytes of data:
Reply from 192.168.2.1: bytes=1462 time=2ms TTL=64

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 2ms, Maximum = 2ms, Average = 2ms


.......snipped

C:\Users\rob>ping -f -n 1 -l 1472 192.168.2.1

Pinging 192.168.2.1 with 1472 bytes of data:
Reply from 192.168.2.1: bytes=1472 time=1ms TTL=64

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 1ms, Average = 1ms

C:\Users\rob>ping -f -n 1 -l 1474 192.168.2.1

Pinging 192.168.2.1 with 1474 bytes of data:
Packet needs to be fragmented but DF set.

Ping statistics for 192.168.2.1:
    Packets: Sent = 1, Received = 0, Lost = 1 (100% loss),

Obviously the MTU of my "ipod" is 1472 since that is the max it can receive without fragmentation, so then you could change your router to have a max mtu of 1500 or the PC mtu to 1500 (there is a 28 byte header to be allowed for). However this may affect other activities so make sure you remember what it was set to before

It may be the case that the ipod is "taking too long to fragment or reassemble the packets" that causes your problems. But first try setting the router to use only "b" as I suggested earlier.

moneyuser

I try setting the router to b mode only, although I had a quick look and couldn't find the setting to do this. Will have to look into this in more detail or try a different router.

I will also look into your suggestion about the packet size debitcardmayhem.

The app itself does have some basic graphics, < 10KB and no more than 5KB is displayed on screen at one time. The whole project is 450KB, written in php and connecting to a firebird db. Server is winxp, running apache and php 5.x.

I haven't worked out how much data is being transferred. I am trying to find a profiler so I can find any bottlenecks. I would be surprised if it was the app as sometimes the ipod will work at normal speed and then be slow for the same operation, which I think relates to the networks times of being 2ms and then jumping to 80ms.

I guess I may have to look into other handheld devices but these run windows mobile and are quite expensive. It would be a risk to get one of these to encounter the same sort of problems.

Im_just_careful

I wonder if the very slow responses are the iPod touch doing something else and not responding to the ping.

As a one off test

My iPhone 3GS varies between 37ms and 170 mS with an average of 98mS.

My Android 2.1 phone varies between 5mS and 1082ms (yes really !) with an average of 285mS.

Your concerns may well be valid as lots of software waits for a reply before the next message is made, often people think a problem can be fixed with more bandwidth when the problem is really latency.