SIP Trunk Provider for Business

Looking for recommendations for good quality SIP Trunk provider for work with inclusive minutes to landline and mobile. Looking for around 5 channels with the ability to present any outbound number that we own.

There's the obvious ones such as Gamma resellers but just wondered what else is out there that is recommended.

Also a complicated DDI port to be undertaken as part of the work as ideally only want to port some DDIs to SIP and retain some on ISDN due to legacy modem equipment .

Thanks in advance.

Steve

From experience, you may find issues port just some of a block from ISDN. I have had problems moving from a small ISDN block to PSTN and then further when it went to VOIP.

You will need to fully check that the numbers can be released.