Comcast Internet (and dialtone) Issues
Comcast is an excellent Internet access value. Yet, due to age of existing Comcast cable drops, customer owned inside cabling, and other factors, the signal quality to the cable modem may be deficient. Below are some guidelines to improving your service.
The physical transport must be optimal
- The cable drop from the mainline to your modem must be RG6 cable.
- Remove old "HBO filters" from the days of an analog cable TV.
- Replace the splitter between outside cable and cable modem with a quality two-way splitter (as pictured) with a favored power port for the cable modem.
We require business grade service
- This provides for installation of an SMC 8014 (or alternate) cable modem.
- This modem has the available diagnostic page shown below
- Business grade service has a higher level of response and technical support. Business grade service also comes with a static IP.
Downstream power needs to be 0db or higher.
Comcast states that a working range is -15db to +15db with lower than -11db as being in the "yellow range". Unofficially, Comcast insiders state it should be at 0db or higher for trouble free performance. The picture below shows a Comcast SMC8014 cable modem diagnostic page with a power downstream power rating. The power levels shown may not provide dependable Internet service over a long term. If you do not have an 8014 modem, call Comcast for the power level ratings.
Downstream signal to noise (SNR) needs to be 30db or better.
This is especially important if the downstream power can not be improved. A weak signal needs weak noise to be heard.
Many factors affect cable modem Internet access quality. Yet, we find that the cable line improvements required for acceptable downstream power and SNR also improve upstream quality and the overall long term stability of the connection.
It is the customer's responsibility to correct any deficiencies on their cable connection. We are available for very detailed consulting on this matter.
Ground the cable shield OUTSIDE the building enterance per National Electrical Code section 800-33
- Cable Grounding. The metallic sheath of communications cables entering buildings shall be grounded as close as practicable to the point of entrance or shall be interrupted as close to the point of entrance as practicableby an insulating joint or equivalent device.
- The grounding conductor shall not be smaller than No. 14. The grounding conductor shall be run to the grounding electrode in as straight a line as practicable.
- Bonding of Electrodes. A bonding jumper not smaller than No. 6 copper or equivalent shall be connected between the communications grounding electrode and power grounding electrode system at the building or structure served where separate electrodes are used. Bonding together of all separate electrodes shall be permitted.
Dialtone issues we have seen
- If you have an internal voice mail system, have your tech check your loss of loop settings to insure your voicemail system will hangup when the caller hangs up.
- Check your Caller ID name at www.fixcallerid.com
- Faxing failure rates may increase vs. a standard POTS line.
