dslreports logo

    All FAQs Site FAQ DSL FAQ Cable Tech About DSL Distance DSL Hurdles »»


how-to block ads

2.2 Troubleshooting

Find out your default gateway by going to start-->run-->winipcfg (ipconfig for XP/2000/NT) and selecting your network card in the dropdown box.

If you have a router, the above process will only give you your router IP, instead you will need to go into your router configuration page and find your default gateway there.

Open up a dos box.

Let's say your default gateway is

Type ping -t

Let the test run for a minute or two then hit ctrl-C to end.

If there is more than 2% packet loss, you probably have a serious problem that needs to be investigated.

If you do have packet loss, try to re-run the test a few times to see if it was just some sort of anomaly or if it's definitive.

by Lex Luthor See Profile edited by drake See Profile
last modified: 2011-07-10 01:07:03

Take a look at how your connection is set up.

Make sure that your splitter is rated to at least 750MHz.

Are you using multiple splitters?

If so, try to get the modem on the first 2:1 splitter.

If you have a 3:1 splitter, make sure you put the modem on one of the 2 splits that have a lower db loss (the db loss for each leg of the splitter will be printed on the splitter itself).

In general, it's best to split the cable only once before it hits the cable modem.

Also, possibly try replacing the splitter, maybe replace some of the cabling, tighten all your connectors, etc and then re-check your levels.

If all that doesn't get you into a good range, it might be time for a service call.

by Lex Luthor See Profile edited by drake See Profile
last modified: 2011-07-10 01:04:28

The first major cause of packet loss would be signal level trouble; as you can check this FAQ entry. Once your signals check out, packet loss is usually a network problem, not a problem inside the house. That said, it is required procedure by Cablevision that each trouble call be qualified with a check by a service tech prior to referral.

This step can be bypassed only if there is documented evidence of others with the same problem on the same node (multiple service issues reported to Cablevision Customer Service); or something else out of whack, such as Cablevision's Network Monitoring Systems reporting a high error count or bad signal to noise (SNR) reading on the upstream at the CMTS.

There have been cases of packet loss (with otherwise good signals) caused by an intermittent connection at the tap, ground block, splitter, or other inside wiring. They want to eliminate these possibilities, first. Also, the service tech can check signal levels, and also see if it's the modem itself that's causing the packet loss.

As a rule of thumb, the following procedure is recommended for anyone reporting packet loss:

    Check signal levels | if any levels are out of spec, all bets are off for packet loss.
    Document it | run ping tests to the default gateway and note the results. See if it's a particular time of day, weather condition, etc. when it happens.
    Contact customer service | request a ping test when the problem is happening. Let them schedule a service call preferably during a 'problem' time.
    • Have patience for the referral process to work.

For any cable operator, intermittent packet loss caused by intermittent noise or interference on the upstream plant is probably the most difficult problem to isolate and fix. It takes some time and considerable effort. Unfortunately, it's also something that the customer usually cannot do anything about themselves.

by Lex Luthor See Profile edited by drake See Profile
last modified: 2011-07-12 05:42:50