MTU 101

Latency vs. packet size

If MTU = 1500, then: (1460+40) * 8 / 1,544,000 = 7.772 ms delay per hop
1 MByte / MSS = 1,048,576 bytes / 1460 = 718.2, or effectively 719 packets to transfer 1 MByte.
Then, to transfer 1Mbyte: 719 packets * 7.772 ms delay per hop = 5588.068 ms, or 5.588 seconds per hop.
If we are transferring our 1 MByte ovfile er 10 hops, it will ideally take us:
(1st packet * 10 hops * 7.772ms delay) + 718 * 7.772 = 5.658 seconds.

If MTU = 576, then: (536+40) * 8 / 1,544,000 = 2.924 ms delay per hop.
1 MByte / MSS = 1,048,576 bytes / 536 = 1956.3, or effectively 1957 packets to transfer 1 MByte.
Then, to transfer 1 MByte: 1957 packets * 2.924 ms delay per hop = 5722.268 ms, or 5.722 seconds per hop.
If we are transferring our 1 MByte file over the same 10 hops:
(1st packet *10 hops * 2.924ms delay) + 1956 * 2.924 = 5.748 sec.

It is obvious then that smaller packets will be transmitted faster

The difference comes from the fact that when using larger packets the overhead is smaller.

For a 10-hop transfer, the additional overhead accounts for just a fraction of a second, however it makes a difference if you consider large transfers over long periods of time.

This difference is a also higher in practice, considering TCP options and the fact that modern TCP/IP implementations tend to use larger headers (additional 12 bytes header space for Timestamps for example).

Also, the above example uses best case scenario, not considering higher latency and congestion.

One has to realize the fact that larger packets will still transit more useful data than smaller packets, and that there is no single "best" solution for all applications.

Therefore, try your own MTU, it may works for you, it may not

Reference

This post has been edited by blacktubi: Jan 2 2013, 08:52 PM

Technically, you notice ping is faster when MTU size is smaller

If you was a gamer TIPS : Use a small MTU

In real time condition, although a larger MTU transmit data at a shorter period but it depends, since Wireless can be affected by endless possibility

Use this to see it's difference


This post has been edited by blacktubi: Jan 2 2013, 09:00 PM

Use this command

The above one is an example for sure don't works

ping 8.8.8.8 -f -l 576
ping 8.8.8.8 -f -l 1420

Don't tweak MF680

As you know this device already a heat beast,

More heat will make it reach the max temp threshold faster

When modem reach the value it will clock down the TX PWR

Therfore, for hot device, high TX may cause reverse effect

TX 33 is not for all modem

Not all modem max TX is 33

I mentioned 33 is for Huawei E372 actually

Don't tweak E398, after tweaked performance degraded.

Don't tweak MF680 too unless you got a fan 24/7

COM5 is not the diagnostics port. It is the communication port

QPST using diagnostics port

Common bug with MR3420 V2.

A few Huawei model is affected

I don't think anyone would spend RM400 for modem + RM150 for activation. I believe soon Maxis will provide free modem and activation to capture customer. Just like how Unifi begins

I wonder how fast would my Umobile be since already 30Mbps now

65Mbps maybe

Soon Umobile do agreement with Maxis = 2*20Mhz in future

They will slowly upgrade, more chance to do marketing and more chance to sell new device and get activation fee

Yes = WiMax advanced + now whole Malaysia Sabah Sarawak everywhere base station, town council cannot kacau

+ Yes got agreement with TM one, TM WiFi got some is running on Yes as backhaul

I prefer if there are more fiber players

At least a promised consistent speed, Maxis is overly congested at some location

I will prefer Georgetown or Farlim if I cannot afford Georgetown

Don't know how Relau perform

Those who can afford Georgetown sure afford a Fiber
Less congestion, only mobile device

Georgetown area also below 1Mbps?
Wow, you should complaint immediately right now
As Maxis takes a long while to solve issue

Yes, those place where I get 25Mbps and up is at those Business district

-2XX > -4XX

Set it like this

Any Qualcoom modem is compatible

Reboot your modem to see the effect

What happen at my location is

There are 10 Apples and 100 people would like to have a slice

Hence, everyone get one but it is a small one

Recently I purchased a better shoe so I can run faster to get bigger apple.

But 80% still on luck, sometime other run faster then me, then I only get the seed

They told me they will bring in more Apple to solve this issue soon

Given ETA by end of January, else told me I can complaint to SKMM

I complaint 6 months ago one

So you still got hope on complaint then go ahead

Learn more powerful English. Somebody here is a very good example for this

My Kampung 2 bars / 3 bars signal can get 10Mbps 4Xms ping one

DC-HSPA+ too

Kampung is always better, food and the warmth