On Tue, 5 Nov 2002, Dave Phelps wrote: > Ok. So you're going to link 2 switches. I haven't used the Multitech units, > so I won't comment specifically on those. I have used Cisco's VoIP hardware, > which I've had good luck with, so my perspective is based on how *I* would > do this using Cisco hardware, but I would imagine you can substitute the > Multitech equipment w/o much trouble.
If I had seen any VOIP implementation prior, this experience would be less painfull. > Since the KXT doesn't support E&M, your only real choices are FXO or FXS. > > >From the perspective of the KXT side... > > If we use FXS, then we will connect to a trunk port. > For outbound calls, that means users will have to press a line button, or > you can set up a separate trunk group, to place tie trunk calls. That's > convenient enough. For inbound calls, if there is no DISA service available, > all incoming calls will have to ring at a designated extension or > extensions. > Inbound callers will not be able to choose the destination extension by > intercom number. As a workaround, you could have the AA answer the calls and > prompt the caller, but that is a kludge that wastes a bit of call setup > time, and uses your voicemail ports. IIRC, there is a DISA module you can > add which should be able to bypass using the AA. > > If we use FXO, then we will connect to a station port. > For outbound calls, users will have to dial the extension number, but you > could program it as a DSS button and label it as a line so the users almost > wouldn't know the difference. Program the FXO port to go offhook when ring > is detected, take the dialed digits and route the call as desired. > On inbound calls the FXO port will simply go offhook (drawing DT) and spit > digits which will correspond to the dialed extension. > > As far as the Norstar side, if they have a Modular ICS, E&M is definitely > the way to go. If they have a Compact ICS, or balk at the price of E&M (E&M > on Norstar requires several extra pieces of hardware that they may or may > not already have), then FXS to loop start trunk ports is the way to go. > Connecting to trunk ports lets you take advantage of the routing tables in > the Norstar. That let's you do a coordinated numbering plan, where the > Norstar users will only have to dial an extension number, and the call will > be routed appropriately. No extra digits, and no trunk group (pools in > Norstar parlance) selection required. If they have a MICS and decide on loop > start and FXS, they will at least need a services cartridge to provide DTMF > receivers for DISA service. If they have the CICS, there are a couple of > DTMF receivers built in. Be warned that Nortel calls DISA service "auto > answer", and "answer with DISA" is optional. You will want the auto answer > feature on the tie trunks, but if you enable "answer with DISA" then the > system requires a 6 digit COS code before it will provide a dialtone. Rather > inconvenient for the controlled access configuration you will be using. I think the Norstar is a Modular ICS. And supposedly, there will be another one in the new office with the VOIP solution providing the trunking between them ( is trunking the right word?). The Multitech MVP810 has 8 sets of ports with each set containing a jack for E&M, FX0, and FXS. Hopefully this is enough flexibility for the phone gent to work with. > The primary reason you don't want to use FXO ports on the Norstar (and I'm > pretty sure the KXT has this same limitation) is because Norstar single line > ports (either ATAs or ASM ports) do *not* provide a CPC signal. This means > that if you have an active call using a Norstar analog port connected to an > FXO connected to a far end FXO connected to a Pana station port, no call > will ever end. The VoIP equipment will never receive a disconnect signal, > and so will never drop the now inactive call. > Noted, and heck, the phone guy may even know this already. I hope so. > Another reason not to use FXO on the Norstar is because you won't be able to > use the routing tables, and users will have to dial the extension # and wait > for DT to place a call, just like the KXT. > > Got to run, but I can answer additional questions. > > In summary, depending on the Cisco equipment already in place, I would be > inclined to use the Cisco stuff directly rather than the Multitech stuff. In retrospect, I probably would too. Maybe not Cisco, but at least the same vendor. Thanks for the voluminous post. _________________________________________________________________ KX-T Mailing list --- http://kxthelp.com/ Subscription changes: http://kxthelp.com/mailman/listinfo/kxt
