How many SIP trunks/channels do I need???

[fiza]

I am a little confused with what I am being told by resellers so I wondered if someone here without a vested interest in selling me something could explain;

 

I need 75 phones in the School. I would like the ability to have at least 15 simultaneous external calls (either incoming or outgoing) at the same time from any 15 of the 75 handsets. I need around 15 Direct Dial In numbers.

 

What do I need SIP wise? Do I need a SIP channel for each phone or is 15 that I need?

[mgs1990]

From what i remember of implementing this a few years ago. you'll need

 

15 SIP Channels (1 channel per outgoing/incoming call) you dont need 1 channel per number/phone unless you want 75 simultaneous calls

Amount of channels per trunk alters with your SIP provider.

numbers can be bought in blocks from BT or your SIP provider.

[fiza]

From what i remember of implementing this a few years ago. you'll need

 

15 SIP Channels (1 channel per outgoing/incoming call) you dont need 1 channel per number/phone unless you want 75 simultaneous calls

Amount of channels per trunk alters with your SIP provider.

numbers can be bought in blocks from BT or your SIP provider.

 

If those 15 SIP Channels come with bundled calls should any of the 75 handsets be able to utilise the bundled minutes?

[Primus]

If those 15 SIP Channels come with bundled calls should any of the 75 handsets be able to utilise the bundled minutes?

 

Yes they will.

[fiza]

Yes they will.

 

In that case I am getting wrong info from supplier. I was told by the supplier that for their system I needed a SIP channel for each handset if I wanted to utilise the bundled calls on it. If I had 15 SIP Channels then they would be allocated to 15 handsets and only they could use the bundled minutes.

[Primus]

Have you got an onsite PBX?

[fiza]

Have you got an onsite PBX?

 

I am playing the FreePBX (without SIP channels) and I have been getting quotes for both on-premise and hosted solutions.

[Katy]

In that case I am getting wrong info from supplier. I was told by the supplier that for their system I needed a SIP channel for each handset if I wanted to utilise the bundled calls on it. If I had 15 SIP Channels then they would be allocated to 15 handsets and only they could use the bundled minutes.

If it's an onsite PBX then that's rubbish, we have 8 SIP channels, 70 handsets and all of them use the bundled minutes (our bill for calls last month was £2, somebody must have dialled an 0845). Sounds like you need a better supplier.

 

(If it's a cloud PBX then no idea.)

[Primus]

Yup we have an onsite PBX (Mitel) and we have 12 sip channels that are used across many many handsets with pooled minutes.

[PotNoodleTech]

Yes medium size secondary and we have 8xSIP channels and 90 phones all share the sip channels and all use the included minutes. Mitel system from a reseller.

 

Get a new reseller as your current one is making it up as they go along.

[mavhc]

SIP Trunks don't exist. Phone companies aren't charged for numbers, or for having numbers assigned to them, only external costs they have are calls, after the initial porting and setup.

 

If you have an internal PBX then you don't even need the provider to know which phone was used.

 

I'd start with n channels, monitor to see if you run out, then ask them to add 1 more at a time

[Edu-IT]

In that case I am getting wrong info from supplier. I was told by the supplier that for their system I needed a SIP channel for each handset if I wanted to utilise the bundled calls on it. If I had 15 SIP Channels then they would be allocated to 15 handsets and only they could use the bundled minutes.

It is sometimes the case that you have to buy a calls bundle per handset, so there may be truth in this. Depends on the supplier. Not all pool the minutes.