Ursine1
join:2007-10-16
Chicago, IL
| [Connectivity] [CHICAGO] Fast Speed Test / Slow Browsing
For the past few days I've been having issues with slow browsing. Pages load slowly; and sometimes I have to click a couple times to load a page. I'm paying for 20 mbps and getting 17+ down on speed tests. I'm using open DNS, and have tried both their servers as well as RCNs (and also leaving it blank) and there seems to be no difference. I've rebooted the Mac, the modem, and the router several times. I've tried taking the router out and direct connecting to the modem. Nothing seems to help. Any suggestions? |
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Ursine1
join:2007-10-16
Chicago, IL | Here's my line quality test:
»/linequality/nil/2416205
I'm showing a fail on "low bandwidth stream" and "medium bandwidth stream"; with a 100% loss on medium. What could that mean? |
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Ursine1
join:2007-10-16
Chicago, IL | reply to Ursine1
Anyone? Bueller? |
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Markk02474
@rcn.com
| My guess is that a few of those routers are congested and/or using a switch traffic flow cache where entries get replaced in milliseconds. When this happens, as with the first packet sent to a destination, the hardware switch fabric can't quickly move the packet, it has to be examined by the CPU. The routing table is used to find the best egress interface, the packet is sent there, and the switch cache gets updated with this destination. Probably some other destination got kicked out of the cache. The problem is that the CPU gets backed up with work and its queue of packets to handle the slow way overflows. The queue length can be tuned, and perhaps its not the best length. Its far better to drop data packets than routing packets, and they may hold space for them. Anyway, this is probably why medium speed transmission gets drops and higher speed not.
There could be a buffer carving issue on the router - lots of small buffers and large buffers and not enough medium sized ones. On the Internet, the greatest number of packets are 64 bytes long (ACKs, ICMP, SYNs etc), next would be full Ethernet frame sized packets. The medium sized packets are not nearly so common, and so one or more routers may be short on buffers that size.
There's not much you can do, however. Hope the backbone network guys notice all the drops and feel like tweaking router parameters after getting approval to do it during a future maintenance window! Not going to happen very often. |
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Ursine1
join:2007-10-16
Chicago, IL | reply to Ursine1
Still happening. Latest speed test:
»/linequality/nil/2416585 |
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jsolo1
Premium
join:2001-07-01 | reply to Ursine1
I'm using 4.2.2.x as my dns and am not experiencing any slow browsing issues.
Have you tried a different machine and/or browser just to rule out the obvious?
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Insanity is living in a state of disillusion. |
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Ursine1
join:2007-10-16
Chicago, IL | Yes. |
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jsolo1
Premium
join:2001-07-01
| reply to Ursine1
Ursine, it might be a localized problem.
Just ran my own line quality - »/linequality/nil/2416598 - which looks pretty decent.
Maybe call rcn up and have them do their own line tests. With the bad storms we've had there may be some water in one of the taps or other which might be contributing to this...
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Insanity is living in a state of disillusion. |
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Ursine1
join:2007-10-16
Chicago, IL
| reply to Ursine1
Calling RCN is a total waste of time; it takes multiple calls and hours of dedication to get anything escalated past the customer service people in India.
At first I was hoping the issue was something I could resolve on my own. Now I'm hoping maybe someone from RCN might see this thread and look into the issue.
I suspect, of course, that nothing will happen. That this will just be yet another moderately annoying problem I'll have to live with, until, several months from now, it mysteriously goes away... only to ultimately be replaced by some new moderately annoying issue.
Ah, life with RCN. |
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jsolo1
Premium
join:2001-07-01 | reply to Ursine1
Please review this post, »Getting Official Help.. .
Your post is missing a critical piece of information.
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Insanity is living in a state of disillusion. |
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Ursine1
join:2007-10-16
Chicago, IL
| reply to Ursine1
Oh, I'm sorry... I forgot to post my Mac address.
Your Modem Mac 00:15:a3:2a:5e:05
Forward Frequency 735000000 Return Frequency 33000000
Forward Modulation qam256(4) Modem TX Power 42 dBmV
Foward Signal to Noise 36.8 dB Downstream Ratelimit 0
Forward Power Level 14.5 dBmV Upstream Ratelimit 0 |
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daveinpoway
Premium
join:2006-07-03
Poway, CA
| Even though it is technically (barely) within the DOCSIS specs, your downstream power level is high. Depending on how tolerant your cable modem is of this condition, this high level may or may not be a problem. I have seen my Motorola Surfboard work fine with levels higher than yours, but other modems may not be so forgiving.
The only thing you can do about this high downstream level is to make sure the modem is not being fed by an amplifier within your house. If you are not using any amplifiers, a tech will need to look into this. |
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Ursine1
join:2007-10-16
Chicago, IL
| No amp. The cable comes thru the wall is split: one to HD TiVo, one to modem. Looking at older info I've saved, it seems that level has always be in that range; the slow browsing issue is a new one. I'm guessing that the within-tolerance downstream power level isn't the culprit here.
Still showing the same line quality problems: 37% loss in low bandwidth stream, and 100% loss in medium bandwidth stream.
»/linequality/nil/2417015 |
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Ursine1
join:2007-10-16
Chicago, IL | reply to Ursine1
Is there anyone from RCN reading this? |
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jsolo1
Premium
join:2001-07-01
| reply to Ursine1
Ursine1, Completely overlooked, but have you tried removing your router from loop? I was discussing your issue with a friend and this was suggested. For some reason I assumed you already tried this...?
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Insanity is living in a state of disillusion. |
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Ursine1
join:2007-10-16
Chicago, IL | reply to Ursine1
I have tried that; mentioned in the very first post.
Anyone from RCN reading this? |
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boble88
join:2001-12-20
Somerville, MA
 ·RCN CABLE
| reply to Ursine1
RCN informed me that the Toshiba router I had was not good for the Mach 20 service. On 8/9/08 I went to RCN and swapped my Toshiba router for a Scientific Atlanta, here is my test.
»/linequality/nil/2418339 |
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Ursine1
join:2007-10-16
Chicago, IL | The problem continues even with my router out of the loop.
The issue isn't slow speeds, it's slow browsing; pages failing to load completely or taking a long time to load. (Although tonight I'm only getting 7-8 mbps.)
RCN? Anyone? |
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Ursine1
join:2007-10-16
Chicago, IL | reply to Ursine1
RCN? Anyone? |
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Ursine1
join:2007-10-16
Chicago, IL
| reply to Ursine1
Over a week later, and the problem continues.
Line quality test results:
»/linequality/nil/2419047
Browsing = Click link. Wait. Wait. Wait. Wait. Wait. View page; partially.
Some pages load completely, most do not.
Anyone at RCN? Please? |
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