atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services T1's, CSU's and DSU's T1 reliability, do I need a backup?

Where I work we currently have 7 POTS lines and two crappy DSL connections (512/512K) (1.5M/128K).

We are in talks about obtaining a Dynamic 1.5M T1 service and connecting our phone system to that. I know very little about the reliability of T1's. Supposedly they are more reliable than POTS lines, but I find that hard to believe.

Anyone out there have real world experience with T1's? Are they more reliable than POTS lines or DSL lines?

Do you think spending $470/mo on a 1.5M T1 circuit and a $60 backup DSL line (1.5/128k) is necessary? Or even keeping an analog phone line?

As it stands switching to the T1 is going to cost us 9 to 14% more a month. So If I can ditch the $60 dsl line it puts us about par with our current setup. -3% to 1% more a month.

It really all depends. I have some customers that lose their service every time it rains and then there are some I never go back and see after installing their service. If your business can live without service (voice and data) for 24 hours or less, then dump the pots and dsl. If not, I suggest keeping a pots line that calls can be forwarded to and keeping the dsl or if you dont need a lot of bandwidth, go to an isdn back up.

Interesting thought. It does appear our firewall supports dial-up connections via serial cable in a wan-failover. So its conceivable.

Do you think ISDN would be better than dial-up?

The number one benefit of a T1 is that it is a direct, dedicated pipe into the Telco. Secondly in the case of pots, if they are true analog pots, an analog to digital conversion is eleiminated which helps thruput. Third, most of the T1 will be transported on fiber and the rest on copper. If your business is far away from the point where the fiber signal is converted to electrical a conventional T1 span will be used. This type of T1 seems to have more issues mainly because of the amount of copper used to connect componets. Newer technology T1s are used on shorter runs can eliminate points of failure because of less copper involved.

A channelized T1 one has twenty four 64kb/s cannels inside it. They may carry voice or data, the configuration is up to you. 12 voice, 12 data, 4 voice, 20 data or you can dynamically switch to any configuration your equipment can handle. Running data at midnight? 1 voice channel for a phone to the data room and 23 channels software connected together to run the data. Then in the morning switch it back to 12 voice and 12 data or whatever.

Many customers choose an ISDN prime T1 to connect from their equipment to the telco. This type of T1 has 23 64kb/s "bearer" channels that can carry voice or data and one 64kb/s "delta" signalling channel. 23B+D. The delta channel does all signaling and control functions for the 23B channels thus allowing the customer to have the full 64kb/s bandwidth availible. When not being used for signaling and control the D channel can be used for other functions.

If your POTs is not reliable chances are that your T-1 wil not be either. Our T-1's travel the last mile on the same crappy copper that makes our POTs stink. Verizon just is not maintaining copper at all in our area. The advantage POTs has over the T-1 is a cable problem only takes out 1 POTs line, the same 1 pair failure on a T-1 takes out all our phone and data.

We also found out after the huricane that most of our POTs and the T-1 come thru a vault that converts fiber to the last mile copper. The vault requires Utility Power to function and has 12 hour backup battery. Guess what happened at the 13th hour of the power failure, we lost all but 3 POTs lines and all the T-1s.

Conclusion is there is lo longer a method to provide reliable phone service anymore and no one at Verizon cares. I should also mention that this is a Fire Dept Dispatch Center and loosing phone service leaves our residents with no way to call for help.

FDTech said it best. There are absolutely zero guaranteed services anymore, regardless of the delivery method used. Gone are the days of five nines.

We either have to depend upon copper that isn't maintained properly or battery-powered substitutes that are a gamble at best. It is a no-win situation.

The last mile of copper has been and will always be the networks Achilles Heel. Until such time that the last mile is converted fiber, Fiber To The Prem, the problems will remain. In our area, not a Verizon, the telco is starting to replce copper cell tower feeds to fiber feeds. The rate of trouble and failure reports to those sites has dropped to almost zero. Hopefully, this trend will continue.

Whatever you do, keep one POTS line that the rest of the numbers can be forwarded to should the T-1 collapse...

You should look into how far you are from the CO, and also for some comparison shopping, all can be found on T-1 shopper website:

https://www.t1shopper.com/

Good luck.