Any Network Guru's?

[Wendelspanswick]

A bit of background, me and my business partner run a small telecoms company that looks after phone systems mainly for the NHS.
We also look after the phones for a large country estate and gardens run as a charitable concern, as they are local to us we basically just cover our costs.
We are going to upgrade their phone system to VOIP (Voice Over IP) so the plan was to install FTTP (Fibre To The Premises) which has been done and get rid of the ADSL, we would then install the VOIP and the guys they use to sort out their IT would sort the network side out. The IT guys have now decided that its beyond them so they want us to sort it out.

They currently have a domestic type setup, an ADSL router which has a non static IP address assigned by their network provider and all their devices are on DHCP.

The FTTP provider has given us 6 static IP addresses:
.85 is the default gateway which I guess is the provider end.
.86 is Cisco FTTP router
.87 is the backup Cisco ADSL router
.88 to .90 are for us to use.

I have tested the connection by setting my laptop to .88, subnet, gateway, DNS server etc. which works.

So my question is how do we replace the existing ADSL with the new FTTP connection, I'm thinking that we need a router that we give a static IP address, DNS server etc. to and get it to act as a DHCP server?

 

[HughF]

Yep... same as we have with our adsl provider at the office, fixed IP goes into the router setup. You can then point your external dns settings to your static IP if required (our domain control is fasthosts so I do it from their web panel)...

 

[MrFluffy]

Don't forget to configure whatever you set up to allocate dhcp leases to a specific part of the subnet, keeping it away from the .8x portion. Its common to have a range thats dhcp and some reserved areas you can keep for static ip allocations.
You don't need a router btw, you already have one and all your devices need to know is what network config to apply to use it. I have dns servers built into my wifi access points one of which is enabled and serves the client with a allocation, the subnet's dns server and the default gateway to get out the subnet (not its own). I normally keep everything on static's but occasionally I get the odd device that won't let you configure a static ip (hd homerun for eg... pants for a network tuner, we had to reserve the lease in the dhcp config so other stuff with config hardcoded could find it correctly)

Re-reading it, you do need something to NAT your existing range, as you've only got two ip's allocated. So yes, a router, with nat and a firewall in it would be needed.
The voip server being behind a NAT gateway will make your life more awkward. Read and digest.
http://www.voip-info.org/wiki/view/NAT+and+VOIP

Be very careful on security on things routable from the external network...

 

[bump]

Any chance of a network diagram?

It looks like you have been assigned a /29 subnet. What's the provider equipment? In the office I have a Juniper EX4200 providing that /29 subnet on the first 5 ports, and a Cisco 1900 that has a dumb switch attached to achieve the number of ports required on the backup /29 subnet.

How many users for both data and VoIP are there? I presume your using IAX2 as the trunk protocol. The reason I ask is as it's a shared connection there doesn't look to be any QoS or bandwidth limiting. In the event of someone downloading the office installer from Microsoft you could have a call quality issue.

You'll need some form of NAT to separate your internal clients from the outside world.