ISDN | CT Wholesale

Exceptional call quality using high performance connectivity

If you already provide a customer’s broadband service, securing their line rental business as well further cements your customer relationship. Even where your customers already have their lines installed by BT Retail or any other BT Wholesale Service Provider, you can still transfer those existing lines to us and continue to benefit from the revenue they generate.

Here at CT Wholesale we can offer the choice of ISDN2 (2-8 channels) and ISDN30 (8 to 30 channels) for larger businesses. Both ISDN2 and ISDN30 will achieve crystal clear voice-call quality, individual DDI numbers and a wide array of call management services. There is also a choice of options to cover lines with Care Packages should they ever be disrupted.

Business Benefits

Stay in control

Secure, dedicated, high-bandwidth connectivity similar to a private circuit service

Low risk

Resilience options to keep your customers' connected


Voice, data, text and applications such as video-telephony all in one circuit, improving efficiency


Ability to add multiples of two channels enabling your business to grow

Greater management

Flexible number configurations helping manage end customers’ calls efficiently


Dialogue services allow you to provide a higher level of service

Why Choose CT Wholesale's ISDN?

Flexible billing options allow for white label branding

Fast, efficient and competitive installation

We will never be beaten on our price or service

Crystal clear voice call quality

Access to a full range of calling and network features

Secure, dedicated, high-bandwidth connectivity similar to a private circuit service

Key Features

ISDN 64k and 128k connections available

ISDN2, ISDN30 and fully managed ISDN services to choose from

Customise the tariff for your customer


If I move customers over to CT Wholesale lines and calls billing to make extra revenue will my customer receive any interruption in service?
No. Transferring your billing provider does not interrupt the service at all.

Can I upgrade from ISDN2 to ISDN30?
No. This is a new installation, it would be worth at this point considering if the phone system on premise supports ISDN30 and if you would be better moving to SiP trunks instead.

Is ISDN a service soon to be retired?
ISDN is an old technology but it still has its uses. There are no plans to retire this technology at present.

Interested in ISDN?

Call Us On:
01246 641 088