I'm installing IP phones on a LAN fed by 2 T1s. One is configured(provisioned?) as 24 data channels and one is an integrated T1 w 14 bundled voice lines and the rest data.

I am uncertain which configuration to use for IP phones- a channelized config or must it be one big pipe?

How about PRI? Can PRI(or should I say B channels) support IP phones?

PRIs and B channels have nothing to do with IP phones except to provide a voice path to the carrier. You can have 50 IP phones and no lines T1 or PRI if you want a large network based intercom.

I agree with what RBF said but I also think we are missing some info.

Can you tell us if this is a hosted PBX application? As in, no PBX at the customer prem? If so, you'll want the largest "data" pipe you can get and close attention paid to QOS. If it's not a hosted pbx solution like Cisco Call Manager, you can have PRIs go right into the IP/PBX and the phones only use a local network for IP connectivity so bandwidth is a plenty and you setup a VLAN for the phones.

I also need to know why they have a full T1 for data and another router with fractional data? We might need to get a better idea of the hardware/CPEs just to understand better. Perhaps they have to separate connections for redundancy or they use one pipe for some type of dedicated server application?

Also, how many phones are you installing and what voice codec are you using? Compression will be a factor in deciding how much bandwidth you need to make available. Of course, this is only a big deal if you are using a hosted pbx solution.

Fred

Here's the full story. First, let me say that I have relatively little experience with T1s, and never installed T1 hardware with a system. I have always programmed PBX switches and now am installing key systems for small businesses. This is my first medium business-sized Norstar install, a BCM 400 with 20 IP phones onsite and 6 IP phone across the street which is connected to the network by a cat 5e cable. I realize I need help, and intend to hire some. Meanwhile, I am trying to get a full picture before the install gets moving along.
The existing key system is a Toshiba which uses an XO integrated T1 bringing in 14 analog circuits to the key system along with 10 data channels remaining. A new T1 was ordered for increasing bandwidth on the data network, and configured for 24 data channels by the network guys from a remote site. Now customer has decided he wants the new T1 to support the new IP phones.

Am I understanding correctly that I should maybe use the analog circuits in the T1 rather than the T1 w 24 data channels? I believe XO also offers DIDs in some deal, but I would like to use what exists.

On a BCM I would do a PRI and get at least 20 DIDs. Setup all of your target lines 1st then worry about how you are going to use them later. As stated IP phones have nothing to do with how you provision the WAN. Your Toshiba most likely had an RDTU as it card, you will use a DTI card on the BCM. I propably still have a cheat sheet for the BCM if you need one.

To reconfigure the T1 for DIDs , XO wants 6 weeks. If we use the current configuration, the BCM can be installed now.

6 weeks is absurd. Kick some ass and take some names. Geez. It shouldn't take anyone with half a brain to reconfigure a TDM trunk as a PRI and route DIDs. Anyone disagree? Mind you I'm not a switch tech but I've seen changes like this done in 15 minutes or less with the right person behind the wheel. (AnthonyH?)

As for adding another data T1 for IP phones...I'd say that based on what I have read above, the PBX is a VoIP pbx with all traffic being handled over the local area network (on a VLAN perhaps?) and you wont be doing offsite IP phones? If that's the case, there wouldn't be a need to beef up your Internet connectivity. Do we know if they plan to do offsite VoIP as of right now? If you do end up bringing in another data T1, do you have a plan in place to share the bandwidth between those data T1s? Are they both going to be from the same carrier? If so, you'll have a choice of MLPPP or Cisco CEF Per Packet or Per Destination load balancing. If you are doing VoIP or QOS on the Internet T1s you'll probably want to stay away from per packet.

6 weeks seems a bit long, they are basically just making you reorder a new ckt, and have the whole thing start from scratch. If they already have the facilites reserved for the T1 they should be able to set this up as a PRI failry easy. You should see if they can expidite a conversion for you, Most of teh VOIP systems that I see are running across PRI's.

But what about the current T1 configuration?

1. Can the BCM 400 with IP phones use a GATM8 card with the integrated T1 bringing in 14 analog lines?

2. Can the BCM 400 with IP phones use a T1 with 24 data channels? I don't see where the dial tone would come from.

jjimm,
How much exposure have you had to the BCM-400 system? In requesting to have 26 IP phones installed, why is your client pursuing the BCM 400 instead of the BCM 200? Is the client wanting to completely replace their current Toshiba system, or are they simply wanting to add the 26 IP phones to their current architecture? The BCM 400 supports 30 to 200 users. However, the BCM 200 supports 20 to 32 users.

1. You would need two GATM8 cards since they are 8-port units. I'm assuming that the carrier is providing a channel bank.

2. What? This is a data T-1? The BCM could use this if you were going to have remote IP phones. Since it has 24-data channels, their will be no dial-tone coming from this T. Unless you're doing some type of SIP trunking.

With all do respect, you seem to be in over your head on this project. I've read several of your other posts about this setup. Are you sure you want to be involved with this project?

Yes,this discussion is beyond my experience. I have programmed T1s ,but never installed a system with one. This is why I'm paying a tech to do the install who is on vacation right now. Until his return, I am trying to understand all I can on my own. I could just sit back and let him do it, but I would learn nothing this way. As a tech I hope to do this on my own after a few of these installs.

data network I now understand we'll be using 14 analog trunks brought in to the BCM by the integrated T1 and will use 2 GATM8 cards for dial tone. The IP phones will be on the data network and make use of the T1 with 24 data channels. Although they use 640k each, more than likely all 26 phones will not be on the network at the same time.

Now I need to learn how to bridge the data channels of the remaining 10 channels of the integrated T1 with the T1 configured for 24 data channels or with a fragmented T1, should it ever be needed for all 26 or more IP phones at once to be on the network. I would also guess that an IP phone would still function at less than 640k (maybe 590k), but the voice quality would degrade as the bandwidth decreased.

Only 6 IP phones will be pulling traffic from the T1, correct? You said you have 20 IP phones on-site and 6 off-site. The 20 on-site phones will not be using the internet to connect to the BCM.

Correction...After re-reading your post in the VoIP section, none of your phones will be using the internet. You stated that you have 20 phones at the main site, and 6 phones at a remote site fed by a Cat 5.

That is correct. When I said "off-site", I meant across the street 500 ft away, but still on the same network. My only concern was the signaling limitation.

It's funny, looking at this in hindsight.I was worried about changing the configuration but now it seems I don't have to reconfigure anything. I feel much better understanding it, however. Thanks to all for the advice!

I'm still wanting to know who the carriers are for the all data T1 and the muxed T1? Combining the two might not be as simple as you think depending on a number of factors. What type of routers are they and what handoff are you getting? 100base ethernet?

Is there a firewall involved and if so, what make and model?

I agree that, as far as I can tell, your bandwidth to the Internet should not come into play here because all of your VOIP traffic will remain on the local network.