RCN cable modem losing speed!!

Razz2525 · Post by **Razz2525** » Tue Jan 22, 2002 5:03 pm

I have an RCN (RCA brand) two-way cable modem that worked ok initially (but had a lot of problems dropping the connection) in August 2001. Because of the continuous problem of dropped signals, they replaced the modem last week, and I no longer have dropped signals (it's been working ok though I frequently lose my TCP/IP connection to AOL for some reason although the modem does *not* go offline).

The problem now is that my download speeds are horrendous. I don't know whether it's my computer's RAM (96Meg) that's the culprit since I've downloaded a lot of mp3 and video clips recently, and started using Morpheus which is a big drain I see, but I'm downloading now at abominable speeds (tops 10 KB/s, lows 0.85 KB/s). It's taking 2 1/2 hrs to download a 16 meg clip that used to take 20 mins tops. This is almost as bad as my Verizon DSL connection which was horrid. Should I use a tweak (although they really messed up my DSL in the past) or re-examine my memory and get rid of some programs? or could it be RCN? It's pretty much the same situation at all parts of the day, not just late at night when there's more activity I see. I tried it early morning and mid-day and the download speed is truly terrible. I loved my cable modem because it used to be 256KB/s at first (at least). RIght now, my bandwidth "instantaneous" test says I'm surfing at 17.8 KB/s maximum. Any ideas to improve my surfing/download rate???

Kip Patterson · Post by **Kip Patterson** » Tue Jan 22, 2002 11:14 pm

Morpheus is probably the culprit. Recheck your download speeds with it uninstalled.

Kip

Razz2525 · Post by **Razz2525** » Wed Jan 23, 2002 11:17 pm

Thanks for your advice - I uninstalled Morpheus and my download speeds increased from 0.85 K/s to 5.8 K/s; however, I'm still noticing an *erosion* of my download speed throughout the process. I don't expect it to be perfect, but I'm just wondering what happened to my 200K/s speeds that I used to have. As it is tonight, in downloading a 9meg real player file, I saw it go from a high of 10K/s down to an average 5.5 K/s. This happened with each file I downloaded. I've never gone higher than 10 K/s lately although this RxTx bandwidth program I tried says my max at any given moment of surfing is 20 K/s. Pretty bad!! Where is all my speed going? Is a tweak the best solution, speed software, or is it really my aging computer? Thanks again...

legalmind · Post by **legalmind** » Thu Jan 24, 2002 8:39 am

AOL= problem........

Razz2525 · Post by **Razz2525** » Thu Jan 24, 2002 8:49 am

Re: AOL - just by having AOL (6.0) on my system erodes my bandwidth? I don't use AOL all the time, sometimes I just go straight to IE 5.5 to surf. Apparently you know something I don't...? Please let me in on the secret.

glen4cindy · Post by **glen4cindy** » Thu Jan 24, 2002 9:56 pm

You might want to make sure that the cable company has the correct MAC address of your modem on your account.

I know in the area where I live, a person can go to Best Buy, buy a modem, hook it up, and they will get a 64 kilobit surf. How long it will work this way, I do not know.

The system is designed to allow any modem to sync up, at which time the tech fills out an online form, submits it to the NOC and within two hours, or by midnight at the latest, the MAC address is entered, and the modem receives it's boot file from the tftp server which sets the upstream, downstream speeds, and other important settings.

Some modems, such as 3Com tailfin's have conflicting MAC addresses. By this I mean that the MAC printed on the modem, and the MAC shown on the internal web page is different.

Since this enormous decrease in speed has happened since your modem swap, it's possible that the tech input the wrong MAC. Or, the data entry person at the NOC entered the wrong one.

I'd call tech support and ask them what MAC address they have on your account. See if it matches your modem.

Good luck.

Razz2525 · Post by **Razz2525** » Wed Feb 06, 2002 10:28 pm

RCN confirmed that the MAC address matches up but that they're having technical difficulties (for the last 2 1/2 weeks?) that will supposedly clear up by midnight tonight. I tried the TCP/IP analyzer and here were my results, if that helps diagnose the problem in the meantime (Using WinMX I actually watched the download speed start out at 36KB/s and then very quickly erode to between 5-8 KB/s. I see others' upload speeds are sometimes as high as 50 KB/s!)

TCP options string = 020405b401010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which is equal to MSS.

Default Receive Window (RWIN) = 4288
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 4288
For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 171.52 kbps (21.44 KBytes/s) @ 200ms
Your RcvWindow limits you to: 68.608 kbps (8.576 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.

MTU Discovery (RFC1191) = ON

Time to live left = 116 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

How do I open up my RWIN values??? Is there a program that can do this for me? I'm not too adept at messing with the registry. Thanks for any tips!!!

mnosteele52 · Post by **mnosteele52** » Wed Feb 06, 2002 10:34 pm

Use the Windows 98 patch here