Real World Small-Medium Office VoIP questions 2

[jlshelton]

Ignoring the sales literature for a moment, how are people really installing VoIP systems in small and medium offices (up to 200 extensions)? These questions are addressed to people with real-world experience, please.

Do you really have engineered networks for the phones, independent of data networks, to assure QOS (quality of service)?

How do you run a "phone line" to the back of the warehouse, beyond the safe limits of 100BaseT wiring?

What supplies power to the phones, since standard ethernet wiring doesn't supply power? Do you need a UPS at every phone to get reliable operation through power failures?

Have your VoIP phone systems met telephone standards for uptime? We used to expect at most a few minutes per year of downtime with phone systems; does VoIP deliver that?

Do VoIP phones support adjunct equipment like faxes, credit-card terminals, etc?

What are the biggest headaches when switching from a traditional EKTS or PBX to VoIP implementations? What do the real users complain about the most?

What are the biggest advantages to switching? What do the users praise the most?

 

[MarvO1]

I'll answer some of your questions from my perspective.
I install a lot of BCM VoIP systems.
We can run most of the digital phones on cat 3 any place (back of the warehouse) since it is not VoIP until it actually leaves the building. We can also use true VoIP sets, but then the 100BaseT wiring standards apply. We also use soft phones on users PC, but then again, the LAN is providing the bandwith until the call goes of the building over VoIP. So, most everything I see is hybrid, with only portions of the systems using true VoIP.
I like this kind of blend because of wiring, bandwith, and power issues.
You will hear other opinions.

MarvO said it

 

[computerhighguy]

I have a SMB installation using Cisco call manager. We ran into wiring costs as the primary reason for switching and a feature poor Telrad phone system. I have about 300 extensions if you include all my analog lines, but I have only about 150 phones on the desktop (we require a lot of analog lines).

So to answer your questions ....

Engineered network:
Yes and no. I don't run any QoS on my internal network within a building (only WAN links and that is if it is needed) except for our wireless network. We already had a 802.1q enabled network using Cisco 3500 series switches (mostly older ones). So we had quite a few options from\ the get go. It was easy to make a new voice VLAN and enabled the switches. But this is about all we did.

Phone line to back of warehouse:
Do you have a computer back there already? If som, you can use that jack. If not, then you have to follow the typical runes of ethernet. Use Fiber, use repeaters, etc. You can also use a wireless connection, but... I would dedicate a few APs in your warehouse just to voice and make sure you use 802.11g or a for the bandwidth. A workgroup bridge would probably work also. This is a great design challenge.

Power:
I mulled over this for quite some time. I felt it was easiest for most phones to put an extra PoE switch into each wiring closet and patch down selective ports for PoE. It was the cheapest and worked well for us. I used black cables for voice (cat5) and used black markers (we call them icons) for each PoE jack. If there is only 1 network jack, the Cisco phones have a built in ethernet switch in them so you can hook your computers into the back of the phone for network access on the switch port's native vlan. You can also use a power brick if PoE is not an option or a power injector. As far as reliability is concerned, that depends on the reliability of your power. The PoE switches are nice since I can supply UPS power to them in the closet.

Up time:
If it is designed properly, then yes you have the uptime you want. Depending on your network setup, you may have the added issue of keeping your WAN links up (if your call control server is accross a WAN). We have 2 Compaq DL380s running our Call Manager. If one fails, the other is there for it. You can even install a thrid for more redundancy.

Analog access:
Fax machines and credit care machines require analog access. I use the VG248 since it is rated for data communications. These are bit more tricky since they require special codecs, but aren't that hard to deliver. There are many different alternatives so make sure the device will deliver needed data speed for a data call.

Headaches:
Probably the biggest headache we had was hooking the two systems together. Our old vendor didn't want to support us (one reason we switched) and didn't know much, if anything, about PRI lines. So I spent countless hours getting the PRI on the old PBX up and running. I am sure they could have done it in a day if they wanted to. I did make everyone change extensions, but thier phone number stayed the same (DID). It was the easiest for me. Except for a few people, the new phone system was greeted with much fanfair. Probably due to the cool lookinng phones. The users like the fact that they can take the phone with them when they go to a conference room or another office.

When it snows, people can connect to a we based interface and forward thier calls to thier house. As a consulting company, this helps ensure revenue comes in even if the weather doesn't cooperate. We use web based services on the phone for many different things. The biggest advantage to me is that it is extensable. If we get a new location all I need is an Internet connection. We setup a VPN form there to here and I send them phones. The locatins could be in India and no one would know the difference.




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