Analog lines vs. IP Phones 3

[jneiberger]

I'm trying to figure out why adding a single analog phone or trunk to a Shoretel voice switch reduces the number of supportable IP phones by five. This makes no sense to me since the voiceswitch shouldn't be doing much for IP phones except call control, which is pretty light.

Are you seriously telling me that if you have a 40/8, for example, and you're terminating six analog trunks and two analog phones, that the switch has no processing power left to do call control for a few phones?

I really like Shoretel's system, in general, but this just seems like a way to get you to buy more of their switches when you shouldn't really need them.

What do you think?

Thanks,
John

 

[jneiberger]

Also, does setting aside any resources for conferencing affect the number of IP phones that can be supported?

 

[redvoip]

Hi,

Well, this is defined by the DSP resources in each ShoreGear switch. Each port's DSP can support up to 5 ip phone or 1 analog port (FXS/FXO), the idea is increase the number of IP extensions and use some required FXS port, such as: fax extension, etc. Always is going to be used the relation 5:1 (ip/analog).

And about conferencing, it depends. By default it is possible to make 3 party conferences without any DSP resource. But, for example: if you need to create a 4 party conference, you need to use 4 conference port = (4 IP load units = 20 ip phones = 4 analog phones).

Additionally it could be used a ShoreTel conference bridge, which support a substancial amount of conferences plus services like application and desktop sharing, IM.


Hope this help.

 

[BE36]

It doesn't look like you need an IP PBX. Just buy an analog key system or hybrid. ShoreTel, as well as other systems, don't/can't work for every customer. That's why most vendors sell several different solutions. Why buy an IP phone system, from any manufacturer, and not use IP phones?

 

[southeasternMI]

The trunks don't count, its just the analog extensions.

 

[justinrphillips]

No trunks and analog extensions both count. You can get around the 5/1 ratio with analog ports by using a SIP ATA device. There are a couple that are certified with ShoreTel. You get 4 analog ports via SIP for every 1 port.