MTU & RWIN values not getting changed

[Karbi123]

I have a 4 Mbps speed PPPoE broadband connection. But the browsing speed is very slow.
I used TCP/IP optimizer 3.0.6 and changed the MTU to 1492 and RWIN to 249920.
I used TCP/IP Analyzer to check the values. It still shows MTU as 1460 and RWIN as 65536.
Could somebody please let me know why the values of MTU and RWIN are not changing and how to change them ?


Client OS: Windows XP
TCP options string: 0204058c0103030101010402
MSS: 1420
MTU: 1460
TCP Window: 65536 (NOT multiple of MSS)
RWIN Scaling: 1 bits (2^1=2)
Unscaled RWIN : 32768
Recommended RWINs: 65320, 130640, 261280, 522560, 1045120
BDP limit (200ms): 2621kbps (328KBytes/s)
BDP limit (500ms): 1049kbps (131KBytes/s)
MTU Discovery: ON
TTL: 41
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

Regards
Karbi

[Rollingstone]

Log into your modem/router then set MTU to 1492, MSS 1452 (if any), save it then post new TCP Analyzer (dont use Chrome, just IE or FF)

[Karbi123]

Hi Rollingstone,
I have the following ADSL modem
Board ID: 96338L-2M-8M
Software Version: 3.08.02.UB.01.14_1357_100807
Bootloader (CFE) Version: 1.0.37-8.7
Firmware Version: UT300R2U.0011.01
Hardware Version: UT300R2U 2.2
Model Name: UT300R2U

I am not able to find MTU and MSS options in this. Could you please where t change these values in ASDL modem

I also have linksys router WRT54GL. I changed the MTU to 1492 and saved.
Here is the new TCP Analyzer


« SpeedGuide.net TCP Analyzer Results »
Tested on: 03.03.2011 08:08
IP address: 117.195.xxx.xxx
Client OS: Windows XP

TCP options string: 0204058c0103030201010402
MSS: 1420
MTU: 1460
TCP Window: 261360 (NOT multiple of MSS)
RWIN Scaling: 2 bits (2^2=4)
Unscaled RWIN : 65340
Recommended RWINs: 65320, 130640, 261280, 522560, 1045120
BDP limit (200ms): 10454kbps (1307KBytes/s)
BDP limit (500ms): 4182kbps (523KBytes/s)
MTU Discovery: ON
TTL: 41
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)


MTU is still 1460 and RWIN syas not multiple of MSS.

[Karbi123]

I am using IE now

[Rollingstone]

Try the following with TCP Optimizer:

General Settings tab:
Custom settings - check
Modify All Network Adapters - check
network adapter selection - your NIC
MTU - 1460
TTL - 64
Checksum Offloading : enabled 0
Windows Scaling - check
TCP Receive Window - 261280
MTU Discovery - Yes
Black Hole Detect - No
Selective Acks - Yes
Max Duplicate ACKs - 2
TCP 1323 Options:
Timestamps - uncheck

Advanced Settings :

--- Internet Explorer Optimization---
Max Connections per Server : 10
Max Connections per 1.0 Server : 10

--- Host Resolution Priority ---
LocalPriority : 5
Host Priority : 6
DNSPriority : 7
NetbtPriority : 8

--- LAN Tweaks ---
Lan Browsing speedup : optimized
LAN Request Buffer Size : 32768

--- Dynamic Port Allocation ---
MaxUserPor : 65535
TcpTimedWaitDelay : 30

--- Type/Quality of Service ---
QoS: NonBestEffortLimit : 0
ToS: DisableUserTOSSetting : 0
ToS: DefaultTOSValue : 0

--- DNS Error Caching ---
NegativeCacheTime : 0
NetFailureCacheTime : 0
NegativeSOACache Time : 0

--- Gaming Tweak - Disable Nagle's algorithm ---
TcpAckFrequency : Enabled 1
TCPNoDelay : Enabled 1
TcpDelackticks : default n/a

Then "Apply Changes" & Reboot
After that, post your new TCP Analyzer !

[Karbi123]

Here is the new TCP Analyzer...

« SpeedGuide.net TCP Analyzer Results »
Tested on: 03.03.2011 11:06
IP address: 117.195.xxx.xxx
Client OS: Windows XP

TCP options string: 0204058c0103030201010402
MSS: 1420
MTU: 1460
TCP Window: 261280 (multiple of MSS)
RWIN Scaling: 2 bits (2^2=4)
Unscaled RWIN : 65320
Recommended RWINs: 65320, 130640, 261280, 522560, 1045120
BDP limit (200ms): 10451kbps (1306KBytes/s)
BDP limit (500ms): 4180kbps (523KBytes/s)
MTU Discovery: ON
TTL: 41
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

It says MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.
In my router setting the MTU is 1492.
Why can't I make MTU as 1500 ?

[Rollingstone]

TCP Settings are correct !

Why can't I make MTU as 1500 ?

I believe because of ISP !