Help on EPN

[AntBan]

Hi experts,

we have problem with EPN, we try to replace the DS1 Facilities between the Definity.

we read throught the whole docs. We are not clear what exact signaling is using from the Definity to the EPN. is it channelize T1 CAS signal or PRI signal or Lucent propietary protocol?

Is it possible to replace the DS1 Facilities(currently using two CSU) to other vendors, e.g. Cisco TCCS?

any advice will be appreciated.

Thanks

 

[clausen]

No you cannot use TCCS to support the EPN. It MUST be a T-1 point to point. My preference is B8ZS and ESF but other framing and encoding schemes can work. These are not really vocie channels. They are time slot paths. Hope this helps

Thanks

Chris

 

[jverseveld]

The DS1 facilities can be T1 (TN574) or E1 (TN1654) with a maximum of 4 facilities per carrier. Every B-channel is seen by the Definity as a TDM slot. A couple of timeslots is used for signalling, this signalling is basically done over the first facility and the second facility also has the capability to carry signalling information. When you lose both the first and second facility, you will lose your EPN. The capacity between the PPN and EPN is determined by the number of facilities (T1=24ch/fac, E1=30ch/fac).
In short:
*protocol is proprietary
*you may use any path between the PPN-EPN as long as you end up on both sides with a TN574/TN1654.

 

[lopes1211]

The DS1C connection uses 256K (4 channels) of 1 DS1 for signalling. It is a proprietary scheme which can shift this 256K data link amongst the ds1's. The remaining channels carry the actual conversations. (i.e. 1 DS1-C link will give you a total of 20 voice conversations, 2 DS-1's would give you 44). Converting the DS1's to something like IP and then back again will probably not work due to a loss of clocking/synch between the PPN and EPN. Muxing DS-1's off of a DS-3 on the other hand to use 4 T-1's for the EPN Link and the rest for WAN connectivity should work fine. -CL

 

[AntBan]

Hi Thanks all for the hints.

looks like Clausen saying the TCCS will not work since the T1 between PPN and EPN is not channalized.

but jverseveld saying it may work as long as both side has TN1654
we have TN1654 both side and TN574.
but we would like to go for cheaper solution, not Pacbell T1 line but go through IP.
and we have solution for channalized T1, all 24 ds0 can bit in and bit out, but could not do the whole T1 span as transparent bit in bit out.

and we worry about just like lopes1211 point out will loss the syn due to IP cloud.

So, experts, can you tell me that between the PPN and the EPN
1.) can be configed other signaling beside proprietary
, is any way to do that?
2.) can be config as channlized instead of the whole T1 pine? will that work.

Thanks much again.

 

[lopes1211]

1) You have no control over the signaling so give up on that part.

2) If I'm hearing you right, it sounds like this may be a small scale single T1/E1 application since you keep referring to a frac T-1 in a roundabout way. I've never tried but I have noticed that the 256K data link stays on the last 4 (or 1st 4, it been a while) of one of the first 2 pipes. This will stay on the first pipe if you only define 1 circuit on te fiber form. I would suspect that you may be able to use channels 1-8 for data, and 9-24 for voice. The last 4 would be the signaling so you'll really only be able to carry 12 conversations assuming the EPN does not try to hunt lowest channel first for the timeslots. Let us know if you try? -CL