Lines & Calls

Voice communication is key to any business and in today’s ever changing marketplace, there are a wide range of options available to serve this purpose including the popular shift to cloud based telephony.

At Online Systems, we still supply standard ISDN and analogue landlines to suit your requirements. From provisioning, to billing to faults, we are here to assist and ensure you get the best for your choice of telephone solution.

We offer competitive pricing and tariffs as well as attractive bundle deals on landline and calls. Our pricing is based on your bespoke requirements and we ensure you get the most for your money.

Should I choose ISDN or Sip Trunk?

ISDN phone lines support voice and data transmission over the traditional copper network. SIP Trunks on the other hand, are delivered through a data connection line.

By 2025, BT Openreach looks to phase out ISDN and with this in mind our experienced sales team will listen to your requirements and help to ascertain which solution will work best for your business in the long-term.

If you already have a preference, our team are on hand to ensure this is set up with as little disruption as possible.

ISDN Benefits

  • Combines both analogue & digital to enhance reception quality
  • ISDN lines are scalable to a degree so you can organise them according to your requirements
  • Provides the user with multiple digital channels
  • Installation time is minimal

SIP Trunk Benefits

  • Almost infinite scalability
  • Low Cost
  • Never miss a call by re-routing
  • Enhanced business communications, regardless of location
  • Disaster Recovery

Get a quote

Please send us an email at and include your Full Name and Company Name and what you would like a quote for.

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