To self-manage and transfer your ISDN lines to TNBN SIPS please fill out your details below and we shall email you an application form to complete and return.
Helpful notes when switching to SIP from ISDN
But the secret to a successful SIP implementation is planning – and the more time you have to plan, the better your chances of a system that works quickly and efficiently from day one.
The time to start planning your SIP implementation is now. And thankfully, it’s easier than you might think.
What you need to do from start to finish – If you require help call TNBN on 0800 019 5562
Quick guide transferring from ISDN to SIP
1. Check that your system and handsets support SIP and you have enough bandwidth for voice calls
In this situation, you can opt for a premises-based SIP PBX or alternatively, an ISDN-SIP gateway allows you to convert the ISDN interfaces on the PBX to a SIP interface. This can then be connected to any SIP provider over an IP connection. A gateway is a comparatively affordable option, available from as little as £800 – although this comes at the cost of some features.
Think about how many people in your organisation use the phone at anyone time. Typically a VOIP call uses 100kbps per call. Make sure you have enough bandwidth so that it doesn’t slow down your internet connection. Some internet providers can split some of your broadband speeds in two parts – one for voice and one for data.
2. Configuration details and broadband firewall ports to open to access TNBN SIP
3. Time frames switching from ISDN to SIP
For reference, the timescales for common migration methods are:
- SIP trunk into a SIP-ready PBX and migrate phone numbers from BT (4 weeks)
- SIP trunk into an ISDN-SIP gateway and migrate phone numbers from BT (6 weeks)
- Implement a new hosted telephone system and migrate phone numbers from BT (4 weeks)
- Replace the PBX, implement SIP trunks to it, and migrate phone numbers from BT (8 weeks)
4. Split your migration into two parts
To help, you can split your migration into two phases – inbound and outbound. This takes large amounts of risk out of the migration.
5. Run your new and old systems in parallel
Ideally, you’ll run your old and new systems (ISDN and the dummy SIP) side-by-side for a short period of time. This creates redundancy, so your roll-out can be incremental and controlled at every stage.
To help you manage this TNBN will provide you will some dummy SIPS before the transfer of your ISDN to SIP takes place.
Of course, this is only possible if you make the transition well in advance of the ISDN switch off date, where your old systems will become inoperable.