Help wanted: adsl tweak

uncommonjo · Post by **uncommonjo** » Sun Feb 05, 2006 11:25 pm

Hi,

This is my friend's network I want to tweak.

1. adsl, ppoe

2. my isp is Tm.net.my , 512 kilo bits

3.

MTU = 1412
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.
MSS = 1372
MSS is not optimized for broadband. Consider increasing your MTU value.

Default TCP Receive Window (RWIN) = 142848
RWIN Scaling (RFC1323) = 2 bits (scale factor of 4)
Unscaled TCP Receive Window = 35712

For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
504896 (MSS x 46 * scale factor of 8)
252448 (MSS x 46 * scale factor of 4)
126224 (MSS x 46 * scale factor of 2)
63112 (MSS x 46)
bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 5713.92 kbps (714.24 KBytes/s) @ 200ms
Your TCP Window limits you to: 2285.568 kbps (285.696 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 120 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000 (0)

4.win xp

5. I'm using a adsl model connected to a router.

The problem is I have used TCPoptimizer to change the Rwin and MTU setting. But the new setting doesn't reflect in the TCPanalyzer page. I've similiar experience before. Should I use Cable nut?

thanks for your help!

uncommonjo · Post by **uncommonjo** » Sun Feb 05, 2006 11:28 pm

http://nitro.ucsc.edu/ statustics

WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 176.13Kb/s
running 10s inbound test (server to client) . . . . . . 138.49kb/s

------ Client System Details ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.5.0-beta2

------ Web100 Detailed Analysis ------
Cable modem/DSL/T1 link found.
Link set to Full Duplex mode
Information: throughput is limited by other network traffic.
Good network cable(s) found
Normal duplex operation found.

Web100 reports the Round trip time = 292.81 msec; the Packet size = 1372 Bytes; and
There were 60 packets retransmitted, 107 duplicate acks received, and 117 SACK blocks received
The connection stalled 1 times due to packet loss
The connection was idle 0.61 seconds (6.1%) of the time
This connection is network limited 99.98% of the time.

Web100 reports TCP negotiated the optional Performance Settings to:
RFC 2018 Selective Acknowledgment: ON
RFC 896 Nagle Algorithm: ON
RFC 3168 Explicit Congestion Notification: OFF
RFC 1323 Time Stamping: OFF
RFC 1323 Window Scaling: ON
Information: Network Middlebox is modifying MSS variable
Server IP addresses are preserved End-to-End
Information: Network Address Translation (NAT) box is modifying the Client's IP address
Server says [219.95.165.145] but Client says [192.168.1.6]

uncommonjo · Post by **uncommonjo** » Sun Feb 05, 2006 11:28 pm

http://nitro.ucsc.edu/ mode details

WEB100 Kernel Variables:
Client: localhost/127.0.0.1
AckPktsIn: 251
AckPktsOut: 0
BytesRetrans: 82320
CongAvoid: 44
CongestionOverCount: 0
CongestionSignals: 4
CountRTT: 128
CurCwnd: 8232
CurMSS: 1372
CurRTO: 610
CurRwinRcvd: 142848
CurRwinSent: 16304
CurSsthresh: 4116
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 594076
DataPktsIn: 0
DataPktsOut: 433
DupAcksIn: 107
ECNEnabled: 0
FastRetran: 3
MaxCwnd: 80948
MaxMSS: 1372
MaxRTO: 830
MaxRTT: 450
MaxRwinRcvd: 142848
MaxRwinSent: 16304
MaxSsthresh: 39788
MinMSS: 1372
MinRTO: 510
MinRTT: 260
MinRwinRcvd: 35712
MinRwinSent: 16304
NagleEnabled: 1
OtherReductions: 0
PktsIn: 251
PktsOut: 433
PktsRetrans: 60
X_Rcvbuf: 103424
RcvWinScale: 7
SACKEnabled: 3
SACKsRcvd: 117
SendStall: 0
SlowStart: 89
SampleRTT: 330
SmoothedRTT: 320
X_Sndbuf: 103424
SndWinScale: 2
SndLimTimeRwin: 0
SndLimTimeCwnd: 10462836
SndLimTimeSender: 2599
SndLimTransRwin: 0
SndLimTransCwnd: 1
SndLimTransSender: 1
SndLimBytesRwin: 0
SndLimBytesCwnd: 594076
SndLimBytesSender: 0
SubsequentTimeouts: 0
SumRTT: 37480
Timeouts: 1
TimestampsEnabled: 0
WinScaleRcvd: 2
WinScaleSent: 7
DupAcksOut: 0
StartTimeUsec: 501916
Duration: 10468589
c2sData: 2
c2sAck: 2
s2cData: 9
s2cAck: 3
half_duplex: 0
link: 100
congestion: 1
bad_cable: 0
mismatch: 0
spd: 0.00
bw: 0.37
loss: 0.009237875
avgrtt: 292.81
waitsec: 0.61
timesec: 10.00
order: 0.4263
rwintime: 0.0000
sendtime: 0.0002
cwndtime: 0.9998
rwin: 1.0898
swin: 64.0000
cwin: 0.6176
rttsec: 0.292813
Sndbuf: 8388608
aspd: 2.99370

Checking for mismatch on uplink
(speed > 50 [0>50], (xmitspeed < 5) [0.17<5]
(rwintime > .9) [0>.9], (loss < .01) [0.00<.01]
Checking for excessive errors condition
(loss/sec > .15) [9.23>.15], (cwndtime > .6) [0.99>.6],
(loss < .01) [0.00<.01], (MaxSsthresh > 0) [39788>0]
Checking for 10 Mbps link
(speed < 9.5) [0<9.5], (speed > 3.0) [0>3.0]
(xmitspeed < 9.5) [0.17<9.5] (loss < .01) [0.00<.01], (mylink > 0) [3.0>0]
Checking for Wireless link
(sendtime = 0) [2.0E=0], (speed < 5) [0<5]
(Estimate > 50 [0.37>50], (Rwintime > 90) [0>.90]
(RwinTrans/CwndTrans = 1) [0/1=1], (mylink > 0) [3.0>0]
Checking for DSL/Cable Modem link
(speed < 2) [0<2], (SndLimTransSender = 0) [1=0]
(SendTime = 0) [2.0E-4=0], (mylink > 0) [3.0>0]
Checking for half-duplex condition
(rwintime > .95) [0>.95], (RwinTrans/sec > 30) [0>30],
(SenderTrans/sec > 30) [0.1>30], OR (mylink <= 10) [3.0<=10]
Checking for congestion
(cwndtime > .02) [0.99>.02], (mismatch = 0) [0=0]
(MaxSsthresh > 0) [39788>0]

estimate = 0.37 based on packet size = 10Kbits, RTT = 292.81msec, and loss = 0.009237875
The theoretical network limit is 0.37 Mbps
The NDT server has a 8192.0 KByte buffer which limits the throughput to 218.56 Mbps
Your PC/Workstation has a 139.0 KByte buffer which limits the throughput to 3.72 Mbps
The network based flow control limits the throughput to 2.10 Mbps

Client Data reports link is 'T1', Client Acks report link is 'T1'
Server Data reports link is '10 Gig', Server Acks report link is 'Ethernet'

trogers · Post by **trogers** » Mon Feb 06, 2006 1:31 am

First, the MTU is not right. Normal values are 1500, 1492 and 1480.

Use the TCP Optimzer again and load the following, twice. Reboot after each loading:

General Settings tab:
Custom settings - check
Modify All Network Adapters - check
network adapter selection - your NIC
MTU - 1500
TTL - 64
TCP Receive Window - 32120
MTU Discovery - Yes
Black Hole Detect - No
Selective Acks - Yes
Max Duplicate ACKs - 2
TCP 1323 Options:
Windows Scaling - uncheck
Timestamps - uncheck
Advanced Settings tab:
Max Connections per Server - 10
Max Connections per 1.0 Server - 20
LocalPriority - 5
Host Priority - 6
DNSPriority - 7
NetbtPriority - 8
Lan Browsing speedup - optimized
QoS: NonBestEffortLimit - 0
ToS: DisableUserTOSSetting - 0
ToS: DefaultTOSValue - 240
MaxNegativeCacheTtl - 0
NetFailureCacheTime - 0
NegativeSOACache Time - 0
LAN Request Buffer Size - 16384
Then select "Apply Changes" and reboot to take effect

Then do the TCP Anlyzer test again.

uncommonjo · Post by **uncommonjo** » Mon Feb 06, 2006 1:58 am

rwin reflects to the new setting. However MTU is still 1412 even though I set 1500 using TCPOptimizer

TCP options string = 0204055c01010402
MTU = 1412
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.
MSS = 1372
MSS is not optimized for broadband. Consider increasing your MTU value.

Default TCP Receive Window (RWIN) = 32120
RWIN Scaling (RFC1323) = 0 bits
Unscaled TCP Receive Window = 32120

For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
504896 (MSS x 46 * scale factor of 8)
252448 (MSS x 46 * scale factor of 4)
126224 (MSS x 46 * scale factor of 2)
63112 (MSS x 46)
bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 1284.8 kbps (160.6 KBytes/s) @ 200ms
Your TCP Window limits you to: 513.92 kbps (64.24 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 56 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 11110000 (240)

Precedence (priority) = 111 (Network Control)
Delay = 1 (low delay)
Throughput = 0 (normal throughput)
Reliability = 0 (normal reliability)
Cost = 0 (normal cost)
Check bit = 0 (correct, 8th checking bit must be zero)

DiffServ (RFC 2474) = No valid DiffServ equivalent. See the TCP Optimizer documentation, or RFCs 2474, 2475, 2597, 2598, 2873.

trogers · Post by **trogers** » Mon Feb 06, 2006 2:04 am

This case will need the advice of mccoffee. He can help you to correct the MTU value.

When your MTU value is solved, the correct RWIN setting can then be selected as it is a multiple of MSS = MTU - 40.

uncommonjo · Post by **uncommonjo** » Mon Feb 06, 2006 2:10 am

but yesterday when you gave me the Cable nut settings. THe new MTU was reflected to the settings we made.

should I try cablenut? and how do I get in touch with mccoffee.

thanks

trogers · Post by **trogers** » Mon Feb 06, 2006 4:10 am

Yesterday, your MTU was already set to 1480 for XP DSL PPPoE system. Cablenut is not able to modify network adaptors like TCP Optimizer. It just follow your MTU setting.

In some comp system, the modem or router has preset MTU value that cannot be changed by tweaking window registry. Changes may have to be done by accessing the hardware drivers.

I am not good with hardware. Wait a while for mccoffee, he is usually online after 10pm your time.

mccoffee · Post by **mccoffee** » Mon Feb 06, 2006 9:12 am

What modem do you own? If you use a router what make and model?

That mtu of
1412 usually not all the time means that there is virtual private network setup,or ics internet connection sharring however though I would try to setup your connection again like shown in this link hopefully it works http://dslnuts.com/pppoe/mtustuck.htm

uncommonjo · Post by **uncommonjo** » Mon Feb 06, 2006 2:17 pm

thanks mccoffee. I was told you are well verse in this area.

my modem is a aztech adsl modem.
my router is a 3com office connect ( wifi )

I can give you the make when i go there tomorrow. Because I"m behind a router. I'm guessing it's the router's firmware that sets the MTU. RIght? then the RASPPOE setting wouldn't work.

mccoffee · Post by **mccoffee** » Mon Feb 06, 2006 3:08 pm

right most of the time it's the router if you are using any virtual private networking software on the computer you might have to go to whatever your vpn client is, and look for spefic instructions on changing mtu.

uncommonjo · Post by **uncommonjo** » Mon Feb 06, 2006 10:50 pm

i'm not using any VPN software. not that I know of. might try the raspppoe software later.

mccoffee · Post by **mccoffee** » Mon Feb 06, 2006 11:05 pm

It could be stuck on the modem too so look up your modem model up just to make sure

Faction · Post by **Faction** » Tue Feb 07, 2006 8:08 am

I'm getting 1484 MTU on mine. Before I used SG Optimizer it was 1492...but with 1492 my web page loading speeds were slower than with it at 1484.