One-way transmission on a T3

I have a client on the distant end of a point to point T3, who cant see my loop that I provide him at the CFA into 'the cloud' with an interconnect provider within the same building. I run clean (15 mins) to a hard loop at the handoff. My mux equipment is located on the 4th floor along with the meet-me-room and goes through an interconnect riser to the 11th floor to meet the customer. The coax run between the

4th and 11th floors is handled by the building telco provider.

I continue to suggest to the client that the problem is in the cloud, probably cabling somewhere. Bad connector, port or coax cable. To add to the problem, he doesnt have a coax tester, only a test set. He refuses to get the telco provider involved because he's dead set that the problem is on my side. I want to resolve this problem without having to 'train' him on his equipment. I'm a busy man. I suggest that he choose another port on his DACS, have the provider provide a new path or invest in a coax cable tester but he insists that problem is on my side. I basically told him to call me when he's got it figured out. Does that make me a bad technician?

Anyone have suggestions on how to deal with difficult clients? Is there another way that I can prove to him that its within the cloud? Maybe I'm being the difficult one.

Reply to
sjoncb
Loading thread data ...

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@p79g2000cwp.googlegroups.com:

  1. Determine if bothends of the T3 when connected into DS3 terminating equipment can achieve Frame Synch. Assuming that you both are using either C Bit or M13 framing at both ends.
  2. If DS3 frame synch is achieved on both ends, then trade T3 transmit failures with each other. First you fail the T3 by opening your transmit path towards your client. If the client looses T3 fame sych this is at least an initialindication that a DS3 signal path exists.
  3. Restore your DS3 signal, and ask your client to open (Fail) the T3 towards your direction. If the T3 fails at your location, ask the client to reconnect the T3 at his end to restore the system. If the T3 restores in your equioment, this proves out the circuit path from the client to your location.
  4. Possible reasons why your client does not see a loop whenplaced at your location could stem from excessive cable losses between your T3 hand off, and the higher order MUX that is carrying the T3 in question. The DS3 pre-equalizer build out in the MUX equipment at your end may be too low to support a hard wired loopback.

You should consider providing a regenerated T3 loop towards your client end, or alternatly, ask your client to provide you with a hard wire loopback at his interface. Or a loopback n his DCS frame. Depending on DCS equipment vendor, a T3 interface card Line Loopback may or may not be regenerated signal. An internal loop in the DCS would be more appropriate.

Below are cable loss characteristics for the most commonly used Coax cables that support DS3 services.

CABLE LOSS at 22.368 MHZ per 100 feet. AT&T 734 Cable = 1.15 DB per 100 ft. AT&T 735 Cable = 2.18 DB per 100 ft.

The maximum one-way insertion loss between a MUX DS3 card and a DSX-3 is

5.5dB. Assuming that coax cable insertion loss between the MUX at your end and your local T3 interface is not longer than 5.5dB. If the measure loss is greater than 5.5dB, the local MUX pre-equalizer setting should be set to the Long position. If not, thena T3 regen will be required at some theoretical mid point to meet the DSX-3 requirement. Assuming that you meet DS3 handoff requirements, you should be able to maintain frame synch with a hard wired loop.

The above also assumes tha the DS3 signal at your hand off is at a nominal 0.0dBsx (+/- 3.75dB) and at a nominal frequency of 44,736,000Hz (+/-895Hz).

The DSX-3 specifications apply to both ends of your DS3 circuit.

Things to consider:

SETTING LBO Line Build Outs (LBOs) are hardware or software option settings at the transmitter or source equipment to pre-distort orpre- shape the transmission waveform. This compensates for variations in cable length and other operational environments between the signal source and the DSX equal-level point.

The LBO must be set according to coaxial cable type and distance to the DSX-3. See Table below for cable types and maximum distances to DSX-3.

If LBO adjustmentdoes not produce a measurement within the level ranges above, this may indicate the maximum coaxial cable distancewas exceeded. In that case a circuit design engineer may need to install a DS3 Repeater.

Inspection should also be made for faulty coaxial connector crimps that reduce signal strength.

CABLE TYPE Max length Max Length Max Length MUX to DSX3 DSX-3 Patch Mux to Mux W/WO Tie Cbl

Lucent 728 450 FT 27 FT 927 FT Lucent 735A 450 FT 27 FT 927 FT Lucent 735A 250 FT 27 FT 527 FT Lucent KS 19224 150 FT 27 FT 327 FT Mini Coax Cbl

Regards,

Bill

Reply to
Bill

Bill... many thanks. The vendor DACS equipment that I'm using is a Turin TransNav. The framing that I've suggested within the DLR to our client is M23 and we've verified the T3 signal path but I'm going to look more into a possible LBO issue. Thanks again.

Bill wrote:

Reply to
sjoncb

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.