Can tweaking MTU etc improve iBurst performance?

G

gnf

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Good day,

Should I be tweaking my network settings like MTU etc?

Kind regards

gf
 
Well we're not winning . . .

First time user, installed two days ago.

First evening it wasn't too bad - at around 23:30 and past midnight.
Downloading that Zip file mentioned elsewhere on this forum . . . the MS-Windows download box showed between 8.xx and 9.xx KB/S . . . not that much better than dialup, but a slight improvement. :confused:

The next day, my wife complained bitterly about how much slower it was, and that she was battling to get email through.

It's been suggested that we go get an antenna, that 99-100% signal strength doesn't actually mean a damn thing.


Anyhow, since then we have tweaked MTU settings as per DrDCP email sent from iBurst guys. (Fortunately I read the screen display before applying the firmware upgrade suggested in the same email - else I would have regressed the firmware to last year !! <sigh>)


Our reseller (Inteprise) has now proposed some DNS setting changes and after this latest reboot, we'll see if it helped at all. They also suggested we use the Ethernet port instead of the USB one . . . so guess I'll have to install another network card in that machine.

Signal : 100%
Tower: Will check tonight - but suspect we're on the "overloaded" Kyalmi tower (Sorry Halicon :p ).
 
I don't have personal experience on this, but saw this recently on an (internal, pvt) mailing list:
"If you are setting up a VPN for a customer using Iburst the best MTU to use is 1324 and if you are using a normal router or computer then use 1352."
Looks interesting ..anyone keen to try it out and confirm efficacy? :cool:
 
I've either been in a coma for a few weeks or just missed a thread. What's this MTU thing everyone is talking about?
 
A simple explanation of MTU. The data sent over a network is broken down into small manageable packets, sort of sending a few pages of a book in a lot of envelopes by post instead of the complete encyclopedia Britannica one shot. The MTU defines how large the switches, routers and in our case the Iburst modems can handle these packages. Imagine a 12 year old boy trying to carry a 50 Kg bag of Cement compared to a 20 year old, very likey the 12 year old would have to chop this into two seperate 'packages'(MTU's). Thus the suggested 1352 byte setting. Now this package of information, which contains over and above the data, the destination address, as well as the sender's address, and depending on the protocol, various other bits of information. In the situation of a VPN over the tcp/ip protocol, there is a bit more info that gets carried along with the encryption, thus this extra info is going to increase original packet size. Thus the requirement of reducing the MTU to 1324 to allow everything to be carried at one shot.

I hope this simple analogy gives you an idea how these MTU's affect your networking.

Regards
Patrick
 
iConnect logfile for reference

Via iConnect - many towers, two unknown ones seem best.
Is this as good as it gets . . . generally around -100db signal, high latency.

<2006-07-13 22:05:29.140> Unknown Tower (25),-84,1157 ms to www.iburst.co.za
<2006-07-13 22:05:39.156> Unknown Tower (31),-93,1172 ms to www.iburst.co.za
<2006-07-13 22:05:49.171> Sandton City,-94,Timeout
<2006-07-13 22:05:59.187> No Tower (Uplink Failed),-99,797 ms to www.iburst.co.za
<2006-07-13 22:06:09.187> Unknown Tower (25),-85,1125 ms to www.iburst.co.za
<2006-07-13 22:06:19.203> Sandton City,-93,422 ms to www.iburst.co.za
<2006-07-13 22:06:29.203> Unknown Tower (31),-94,1172 ms to www.iburst.co.za
<2006-07-13 22:06:39.218> Bryanston,-100,688 ms to www.iburst.co.za
<2006-07-13 22:06:49.218> Unknown Tower (25),-84,391 ms to www.iburst.co.za
<2006-07-13 22:06:59.218> Unknown Tower (31),-91,422 ms to www.iburst.co.za
<2006-07-13 22:07:09.218> Sandton City,-92,688 ms to www.iburst.co.za
<2006-07-13 22:07:19.218> Bryanston,-98,782 ms to www.iburst.co.za
<2006-07-13 22:07:29.218> Unknown Tower (25),-85,329 ms to www.iburst.co.za
<2006-07-13 22:07:39.218> Unknown Tower (31),-93,1141 ms to www.iburst.co.za
<2006-07-13 22:07:49.218> Kyalami,-104,1157 ms to www.iburst.co.za
<2006-07-13 22:08:19.234> No Tower (Uplink Failed),-99,688 ms to www.iburst.co.za
<2006-07-13 22:09:59.250> Fourways,-111,1969 ms to www.iburst.co.za
 
If I have it set at the router level, do I have to make sure that individual computers also have MTU set to 1352?
 
Not as far as I know Jongi, the router controls your internet connection, not the PC's. The PC's are simply taking a ethernet connection from teh router, so their MTU is not important.. I think. I tried xhnaging all my PC MTU's a while back, but it made no difference that I could see.
 
That's what my thinking is. Suppose wanted a second opinion.
 
Methuselah said:
Via iConnect - many towers, two unknown ones seem best.
Is this as good as it gets . . . generally around -100db signal, high latency.

<2006-07-13 22:05:29.140> Unknown Tower (25),-84,1157 ms to www.iburst.co.za
<2006-07-13 22:05:39.156> Unknown Tower (31),-93,1172 ms to www.iburst.co.za
<2006-07-13 22:05:49.171> Sandton City,-94,Timeout
<2006-07-13 22:05:59.187> No Tower (Uplink Failed),-99,797 ms to www.iburst.co.za
<2006-07-13 22:06:09.187> Unknown Tower (25),-85,1125 ms to www.iburst.co.za
<2006-07-13 22:06:19.203> Sandton City,-93,422 ms to www.iburst.co.za
<2006-07-13 22:06:29.203> Unknown Tower (31),-94,1172 ms to www.iburst.co.za
<2006-07-13 22:06:39.218> Bryanston,-100,688 ms to www.iburst.co.za
<2006-07-13 22:06:49.218> Unknown Tower (25),-84,391 ms to www.iburst.co.za
<2006-07-13 22:06:59.218> Unknown Tower (31),-91,422 ms to www.iburst.co.za
<2006-07-13 22:07:09.218> Sandton City,-92,688 ms to www.iburst.co.za
<2006-07-13 22:07:19.218> Bryanston,-98,782 ms to www.iburst.co.za
<2006-07-13 22:07:29.218> Unknown Tower (25),-85,329 ms to www.iburst.co.za
<2006-07-13 22:07:39.218> Unknown Tower (31),-93,1141 ms to www.iburst.co.za
<2006-07-13 22:07:49.218> Kyalami,-104,1157 ms to www.iburst.co.za
<2006-07-13 22:08:19.234> No Tower (Uplink Failed),-99,688 ms to www.iburst.co.za
<2006-07-13 22:09:59.250> Fourways,-111,1969 ms to www.iburst.co.za
Click to expand...

Shame man, this is terrible. Is the problem here tower jumping? We dont realy get that here in Cape Town, but to sort it out you should invest in one of the new antennas that focus on one specific tower. Hopefully the one with the best signal, if you set things up right.
Should be very much worth the money and your time to get this right.

Jongi: I dont think you need to worry, if it is set at router level it will be fine. That is your internet connection, but then again maby having the cables/devices all set at the same MTU will make it a bit better some how?
But I promise there is nothing you are missing out on, Ive tried it already.
 
It does help

Hi all

If using a router i do recommend setting the nic's on the individual machines to a mtu of 1352 as well. This has been seen to improve throughput slightly and sort out certain mailing issues.


Cheers

Shaun Green
 
I would think that local network performance would degrade slightly if you had to reduce the MTU of individual machines behind the router. I've never experimented along these lines though.

Regards
Patrick
 
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