We have just installed an ESI-50 to connect with an ESI-1000 with ESI-LINK. We have done this at a school just to connect an analog paging system to the IP phones at the school for overhead paging. So, we have an ESI-1000 connecting roughly 300 IP phones at 5 different schools and have installed a 50 at one of the schools just to connect to analog paging through an open CO line port and allow the IP phones to page overhead through an ESI-LINK speed dial to that CO line. The ESI-LINK is working correctly and you can page overhead correctly however there is a long delay after you press the speed dial before the paging system answers. It's like it takes the system 8 seconds to dial back through the ESI-LINK connection to access the paging? They are not happy with this in the event of a lockdown. I have tested the connections at both locations and both are over 100 meg down and 25 meg up and the latency doesn't seem to be an issue? Is there anything ESI can adjust to shorten the delay?

What happens if you try to page locally from the 50?

It's been a while but I know at one point the 50 had less options for the compression codec (726 only I think) and the other system(s) would need to be dumbed down to match. Just a thought.

It does respond quicker from the 50 cabinet on site than through the ESI-LINK speed dial

Quicker meaning "normal" operation or just less of a lag/delay but still some delay?

Did you look into the Codec issue? If I remember correctly the correct way to do it is to match the 50 so you would have to set thre 1000 to G.726. If you're using a bunch of IP phones that isn't ideal. Worst case you could swap out the 50 cabinet for a 100.


Lastly what does ESI tech support say?

It does page normally from the 50 locally. There is only a delay through ESI-LINK. I do have both codec set to G.726 because of the 50 being limited to that codec. Tech Support said to look further into it being a network issue which I don't believe it to be at this point? I can order a 100 to test and see if the G.729 would be a solution. Are you saying that many IP phones are not ideal to use with the G.726 codec? Thanks

The 726 codec results in a bigger amount of data which obviously eats up more bandwith. If they haven't been having voice quality issues then it isn't an issue.


What type of circuits do they have …. if they are just internet and not MPLS or a private WAN then your issue may very well be the Wide Area part of their overall network.

How is the voice quality on calls between different sites?

If you have a 100 I would definitely try it - you would be sending less data which certainly can't hurt. If you have to order it first I would ask ESI if they think it's worth trying.

Maybe....you could just install 1 IP Phone at the school ..tie the paging into the speaker output of the phone..

I just did this very same thing , cheap and it works.

I have used an IP phone speaker output at other locations before but this particular paging system is a Valcom Class Connection and it sends a continuous output tone which wont work with the speaker output of the phone? It creates a short.

I'm not familiar with that ( But...Valcom does make all kinds of Interfaces...)

Since your paging is connected to a CO port on the 50 try adjusting the open loop duration in programming (on the 50). I had a similar issue with a phone line coming from a Comcast EMTA over ESI-Link. The line worked correctly from the local side but from other ESI-Linked locations there was a huge delay or it wouldn't connect at all. Adjusting the open loop duration resolved the issue for me.