ISDN 的声音 服务

业务 Phone 服务

首页产品 & 服务ISDN 的声音 服务

Consolidate 和 simplify your voice services while reducing costs. A single network 和 supplier means one, 减少, 固定费用, with extra savings to be made by centralising the telephony network through consolidation of Local Area Codes.

Using the ISDN Service in combination with Colt 业务 Internet Access can further decrease your costs 和 once you are fully IP ready, you can easily migrate to a SIP中继 Service, which is even more cost effective.

Pan-European reach with reliability guaranteed

Our robust network is protected by Dual Homing, Disaster Recovery or Inbound Call Re-routing services, ensuring your business stays up 和 running should the unexpected happen. Because we fully own 和 operate our own network across 50 geographically diverse, carrier grade switches 和 SIP中继 POPs, we can guarantee a seamless experience across 13 countries in Europe, compliant with all legal 和 regulatory requirements.

Flexible 和 transparent

Online call detail records (CDR) give you complete visibility of call spend 和 traffic, while 所有 Inclusive or Bundled Minutes with Flat Fees or Pay-As-You-Go tariffs suit customers of all sizes 和 traffic levels.

Our own number pool across Europe as well as extensive porting capabilities allows you to keep your current numbers, or add new ranges, with no disruption to the business.


Next Generation IP 技术 can help customers transition from legacy telephony to new voice technologies, 如 SIP中继 和 Unified Communications, enabling them to stay competitive 和 agile. With over 20 years’ experience, 和 the most comprehensive Pan-European network, Colt is the ISDN provider of choice for thous和s of businesses across Europe.


Emergency Calls in Japan

Want to learn more about our business phone services?
Check out the rest of the products below.

SIP中继 服务
With SIP中继 you simplify all your telecommunications into a single IP network. You keep all the features of traditional telephony, 和 call quality, while gaining a monthly cost saving as high as 50%.

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Smart city 和 communication network concept. abstract mixed media.


Salesl和 banks on Colt for its switch to VoIP. Salesl和 focuses on supporting businesses that want to outsource their sales services.

Close-up Of An African Man Using 的声音 Assistant On Cellphone

Colt Intelligent Communications

Colt Intelligent Communications brings together the power of Microsoft’s cloud productivity applications with enterprise communication tools, closely integrated to deliver everything needed to collaborate 和 work efficiently.


业务es finding their voice to empower customers

业务es are seemingly finding their voices once again, with research showing that voice is likely to become the principal medium for dealing with the most complicated 和 potentially most business-critical customer interactions. …