magicJack and magicJack Plus Support, Reviews, FAQs and Hacks

SteveHC

Today I learned a real lesson on the importance of good coaxial connections when it comes to solid MJ/VOIP - and Internet in general - performance.

Over the past week or two I first noticed my MJ VOIP performance deteriorating - audio "dropouts," disconnects, my being able to hear the person I called but them not being able to hear me, etc. Naturally, I assumed it was MJ and/or my MJ+ that was screwing up; "resetting" it didn't really help. But then I started noticing what *appeared* to be a general Internet slowdown at my home, and then later Internet disconnects and modem reboots started, even though Speakeasy.net's advanced tests indicated that my speeds etc. were OK. Eventually the modem reboots increased in frequency, and although my modem indicated that my downstream power level was roughly the same as it had always been (-3 to -6), upstream power had gone from consistently 36 to well over 40 to 46 and probably higher (that is a BAD thing). Given that my ISP's (Comcast) local node has tended to act up annually, I figured that maybe it was doing so again so I had them come out, showed them my Net Uptime Monitor printout, etc.

The tech checked everything out, and what he discovered surprised me:

Even though the coax installation - from the street pole connection all the way to my modem indoors - was done with entirely brand new and high quality cabling and compression (not crimped) connectors no more than about 4 years ago, the connectors were shot; within one of them (indoors no less) the cable was so loose it was barely making contact with the connector. So he replaced all of the connectors - up on the street pole as well as indoors - and when he saw that I was using an off-the-shelf coaxial cable with crimped connectors to connect my modem to my wall jack he cut the connectors off and put on compression-fitting connectors instead.

The result: A difference like night and day. Downstream power at the modem is now a perfect ZERO (you can't get better than that), upstream is back down to a more normal 39-40, Internet connection latency is lower, jitter is now a perfect ZERO, packet loss is consistently zero, MJ is back to working perfectly, and web pages are back to loading nearly instantaneously even though I only have Comcast's entry-level 3 MBPS downstream service. Who knew that even professional and professionally-installed coax connectors can start crapping out after only 4 years?!

And here are another 3 tips/factoids that I learned:

1. The UPSTREAM signal quality is *far* more important to overall Internet performance than most people (myself included, up until now) realize. And by "quality" I do not mean just the upstream power level. Its signal-to-noise ratio - which modems CANNOT detect (they can only detect the downstream S/N ratio) affects not only VOIP performance but even general web browsing performance.

2. NEVER use coax cables with crimped connectors in your tv and/or Internet setup; there's a reason why professional installers now use only compression fittings: the metal crimps effectively act as an exposed "antenna," introducing noise onto the line - particularly onto the UPSTREAM signal. The noise that's introduced onto the line in this manner can actually ultimately cause damage to the operation of the system's local node and thus adversely affect all customers on that node, not just your own installation.

3. Although compression fittings therefore perform best, they do seem to exhibit one disadvantage over time: over time, the coax cable tends to dry out and therefore its diameter can shrink a bit (especially in attics and outdoors), sometimes just enough to loosen or even almost completely eliminate contact between the cable's outermost wiring and the connector. This obviously ruins the signal transmission - especially upstream - and can ultimately result in intermittent or even complete Internet connection failure. Sometimes this can cause the connector to become so loose from the cable that it practically falls off of the cable. This, of course, is in *addition* to connector and wire corrosion and pitting.

Live and learn... Wink

magicJack and magicJack Plus Support, Reviews, FAQs and Hacks

The Importance Of Good Coaxial Connections and Connectors