Help optimizing comcast cable connection please

[1411506]

Hi - I live in Denver and my high speed had never been what it's advertised to be - I am forever trying to tweak, but am unable to get close to what I should.
Comcast advertises 6Mb and here are the results from TCP Analyze and http://nitro.ucsc.edu/-

Thanks in advance for any help.

« SpeedGuide.net TCP Analyzer Results »
Tested on: 09.28.2007 17:20
IP address:

TCP options string: 020405b40103030101010402
MSS: 1460
MTU: 1500
TCP Window: 128480 (multiple of MSS)
RWIN Scaling: 1
Unscaled RWIN : 64240
Reccomended RWINs: 64240, 128480, 256960, 513920
BDP limit (200ms): 5139kbps (642KBytes/s)
BDP limit (500ms): 2056kbps (257KBytes/s)
MTU Discovery: ON
TTL: 45
Timestamps: OFF
SACKs: ON
IP ToS: 00100000 (32)
Precedence: 001 (priority)
Delay: 0 (normal delay)
Throughput: 0 (normal throughput)
Reliability: 0 (normal reliability)
Cost: 0 (normal cost)
Check bit: 0 (correct)
DiffServ: CS1 001000 (8) - class 1 (RFC 2474). Similar forwarding behavior to the ToS Precedence field.



http://nitro.ucsc.edu/ results -
WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
checking for firewalls . . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client-to-server [C2S]) . . . . . 361.0kb/s
running 10s inbound test (server-to-client [S2C]) . . . . . . 6.11Mb/s

------ Client System Details ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.6.0_02

------ Web100 Detailed Analysis ------
Cable modem/DSL/T1 link found.
Link set to Full Duplex mode
No network congestion discovered.
Good network cable(s) found
Normal duplex operation found.

Web100 reports the Round trip time = 87.19 msec; the Packet size = 1460 Bytes; and
There were 3 packets retransmitted, 226 duplicate acks received, and 88 SACK blocks received
The connection stalled 1 times due to packet loss
The connection was idle 0.31 seconds (3.1%) of the time
C2S throughput test: Packet queuing detected: 1.84%
S2C throughput test: Packet queuing detected: 0.49%
This connection is receiver limited 11.09% of the time.
This connection is network limited 88.75% 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

Server 'nitro.ucsc.edu' is not behind a firewall. [Connection to the ephemeral port was successful]
Client is probably behind a firewall. [Connection to the ephemeral port failed]
Packet size is preserved End-to-End
Server IP addresses are preserved End-to-End
Information: Network Address Translation (NAT) box is modifying the Client's IP address
Server says [] but Client says []

[trogers]

Refistry settings seem correct. NDT indicates packet losses and connection stalling.

Do a tracert to www.yahoo.com and post.

[1411506]

Thanks - here ya go...

Tracing route to yahoo.com [216.109.112.135]
over a maximum of 30 hops:

1 1 ms <1 ms <1 ms 192.168.1.1
2 * * * Request timed out.
3 10 ms * 8 ms ge-2-2-ur01.littleton.co.denver.comcast.net [68.
86.105.73]
4 8 ms 7 ms 9 ms te-8-2-ar01.denver.co.denver.comcast.net [68.86.
103.33]
5 7 ms 9 ms 9 ms 68.86.104.126
6 8 ms 9 ms 9 ms 12.116.159.13
7 35 ms 36 ms 36 ms tbr1.dvmco.ip.att.net [12.122.86.250]
8 37 ms 36 ms 39 ms tbr2.sffca.ip.att.net [12.122.12.133]
9 36 ms 36 ms 34 ms 12.122.114.73
10 36 ms 38 ms 38 ms 12.86.154.18
11 82 ms 83 ms 83 ms so-1-1-0.pat1.dce.yahoo.com [216.115.101.129]
12 84 ms 83 ms 88 ms ge-1-0-0-p110.msr2.dcn.yahoo.com [216.115.108.45
]
13 83 ms 83 ms 83 ms ge5-2.bas1-m.dcn.yahoo.com [216.109.120.151]
14 82 ms 83 ms 84 ms w2.rc.vip.dcn.yahoo.com [216.109.112.135]

Trace complete.

C:\DOCUME~1\ROB>

[trogers]

What kind of firewall are you using? It is blocking pings at your modem in hop 2.

Turn off your firewall, both in the comp and the router and do another tracert.

[1411506]

No firewall being used on computer - am using Linksys router, and the only enabled part of the firewall there is Filter IDENT(Port 113) and am unable to disable this..

[trogers]

http://nitro.ucsc.edu/ results -
WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
checking for firewalls . . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client-to-server [C2S]) . . . . . 361.0kb/s
running 10s inbound test (server-to-client [S2C]) . . . . . . 6.11Mb/s

------ Client System Details ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.6.0_02

------ Web100 Detailed Analysis ------
Cable modem/DSL/T1 link found.
Link set to Full Duplex mode
No network congestion discovered.
Good network cable(s) found
Normal duplex operation found.

Web100 reports the Round trip time = 87.19 msec; the Packet size = 1460 Bytes; and
There were 3 packets retransmitted, 226 duplicate acks received, and 88 SACK blocks received
The connection stalled 1 times due to packet loss
The connection was idle 0.31 seconds (3.1%) of the time
C2S throughput test: Packet queuing detected: 1.84%
S2C throughput test: Packet queuing detected: 0.49%
This connection is receiver limited 11.09% of the time.
This connection is network limited 88.75% 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


Your download speed is at 6 mbps but your upload speed is rather low.

Without the ping times at the modem, I would guess from the NDT result your modem may be affected by electromagnetic interference given out by some nearby electrical device. Turn off power to the modem and relocate it a few feet away from all other electrical devices including the router.