{"id":16969,"date":"2017-09-08T15:46:47","date_gmt":"2017-09-08T13:46:47","guid":{"rendered":"https:\/\/www.savecall.de\/all-ip-with-colt-sip-trunk\/"},"modified":"2026-08-06T14:48:43","modified_gmt":"2026-08-06T12:48:43","slug":"all-ip-with-colt-sip-trunk","status":"publish","type":"post","link":"https:\/\/www.savecall.de\/en\/all-ip-with-colt-sip-trunk\/","title":{"rendered":"All IP with Colt SIP Trunk"},"content":{"rendered":"\n

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All IP with Colt SIP Trunk<\/h1>\n<\/div>\n\n\n\n

Trusted Advisor f\u00fcr Sourcing von IT & Telekommunikation<\/h3>\n<\/div>\n\n\n\n
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All IP with Colt SIP Trunk<\/h2>\n<\/div>\n<\/div>\n\n\n\n
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Secure communication via the IP network<\/h2>\n\n\n\n
Is your corporate communication ready for the switch to All IP and SIP trunking?<\/h6>\n\n\n\n
Colt SIP Trunking provides companies with a modern and scalable All IP solution for voice communication<\/a>. It replaces traditional ISDN connections and uses the internet protocol to transmit calls, flexibly, securely and available internationally.<\/p>\n\n\n\n
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To the point:<\/strong><\/p>\n\n\n\n
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Compatible and secure: Supports CLIP, CLIR and encrypted voice transmission via TLS and SRTP<\/li>\n\n\n\n
Flexible connection: Operation via Colt network, IP VPN, Ethernet Private Network or third-party provider<\/li>\n\n\n\n
Scalable costs: Flat rate or per-minute billing per channel can be selected<\/li>\n\n\n\n
Simple migration: gradual changeover from ISDN to IP telephony with a smooth rollout<\/li>\n\n\n\n
Central administration: uniform management of all locations across Europe<\/li>\n<\/ul>\n\n\n\n
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The solution:<\/strong> Colt combines years of experience in the voice sector with a flexible platform that supports both small and international companies with IP migration.<\/p>\n\n\n\n
What this blog post is about:<\/strong> What a SIP trunk is, which features Colt SIP Trunking offers, how the costs break down, and how a smooth migration from ISDN to All IP works.<\/p>\n\n\n\n
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Book a consultation<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n
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Table of Contents<\/h3>\n\n\n\n
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What is a SIP trunk?<\/a><\/li>\n\n\n\n
Features of Colt SIP Trunking<\/a><\/li>\n\n\n\n
Costs of a Colt SIP Trunk<\/a><\/li>\n\n\n\n
Migration<\/a><\/li>\n\n\n\n
How SAVECALL supports your switch to All IP<\/a><\/li>\n\n\n\n
Conclusion<\/a><\/li>\n\n\n\n
Frequently asked questions about Colt SIP Trunking<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n

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What is a SIP trunk?<\/h3>\n\n\n\n
The topic of All IP is omnipresent. Both the specialist portals and the carriers are reacting, among other things, to the ongoing ISDN switch-off. Today we present the Colt All IP solution for medium-sized and large companies: Colt SIP Trunking.<\/p>\n\n\n\n
SIP stands for Session Initiation Protocol and is a voice protocol for VoIP. It takes over the function of the classic ISDN connection by transmitting telephony via the IP network, in other words via the internet protocol. This makes the classic ISDN obsolete. At the same time, however, it means that companies must either reserve part of the bandwidth of their previously used internet line for telephony or connect a dedicated internet line for telephony. You can read more about this in our All IP provider comparison<\/a>.<\/p>\n\n\n\n
Features of Colt SIP Trunking<\/h3>\n\n\n\n
The Colt SIP Trunk offers everything you are used to from ISDN:<\/p>\n\n\n\n
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Inbound and outbound telephony<\/li>\n\n\n\n
Compliance with legal and regulatory requirements (emergency call routing, government monitoring regulations and data security)<\/li>\n\n\n\n
Telephone number management<\/li>\n\n\n\n
Porting local phone numbers<\/li>\n\n\n\n
Direct extension<\/li>\n\n\n\n
Call control<\/li>\n\n\n\n
Phone number transmission (CLIP)<\/li>\n\n\n\n
Call number suppression (CLIR)<\/li>\n\n\n\n
Support for CLIP No Screening and Presentation Number<\/li>\n\n\n\n
Call barring<\/li>\n<\/ul>\n\n\n\n
Colt can look back on over 10 years of experience with SIP trunking. Thanks to the provider’s global positioning, it is possible to set up SIP trunks for all company locations throughout Europe and manage them centrally. Voice traffic is encrypted using TLS and SRTP. The SIP trunk can be connected via Colt’s own network, via IP VPN, Ethernet Private Network (EPN), Internet Access (on fiber optics or SDSL) or via the internet access of a third-party provider.<\/p>\n\n\n\n
Costs of a Colt SIP Trunk<\/h3>\n\n\n\n
The cost of the Colt SIP Trunk varies according to three factors:<\/p>\n\n\n\n
1. Cost of the minute packages<\/h4>\n\n\n\n
You can either opt for usage-based or flat-rate billing per channel.<\/p>\n\n\n\n
2. Bandwidth requirements<\/h4>\n\n\n\n
The rule of thumb is: 100 kbit\/s per simultaneous call. This means that if there are usually 10 employees on the phone at the same time, you need 1 Mbit\/s of internet bandwidth!<\/p>\n\n\n\n
3. Costs of migration<\/h4>\n\n\n\n
The migration from ISDN to an IP solution is initially associated with costs. These can be reduced with a smooth migration, see also our next point. Generally speaking, however, you will need new hardware. This is far cheaper than your previous ISDN hardware, e.g. a softphone solution.<\/p>\n\n\n\n
Migration<\/h3>\n\n\n\n
When switching to an All IP solution, the focus is on migration. Of course, like most providers, Colt offers a support service for the actual commissioning of the trunks. However, it is essential to plan your own costs and roll-out. We are happy to support you with our expertise and years of experience from conception, planning and tendering through to migration management and operation of your helpdesk. Colt offers the option of a smooth migration. This means that the switch to IP telephony takes place in several steps. The first step is to prepare the carrier’s backbone. Once this has been completed, all voice traffic runs over the IP network and the company itself can retain its ISDN hardware for the time being. This makes it possible to gradually switch individual locations completely to IP, for example by integrating softphones as new hybrid hardware. Other locations can continue to use ISDN until the telephone system is completely written off.<\/p>\n<\/div>\n<\/div>\n\n\n

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How SAVECALL supports your switch to All IP<\/h3>\n\n\n\n
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As a carrier-independent sourcing partner, SAVECALL compares Colt SIP Trunking with more than 80 other carriers and SIP trunk providers, for example in our All IP provider comparison<\/a>, to find the solution that fits your channel count, sites and existing phone system. We also support the integration of Colt SIP Trunk with Microsoft Teams<\/a> and a parallel switch to Colt Voice Line (v). We guide you from cost and roll-out planning through to migration management.<\/p>\n\n\n\n
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Conclusion<\/strong><\/h3>\n\n\n\n<\/div>\n\n\n\n
With its SIP trunking solution, Colt offers a good opportunity for medium-sized and larger companies to gradually migrate their telephony. The option of gradual migration gives the ICT department enough time to migrate sites completely to IP hardware and carry out intensive tests at the same time. Other locations remain unaffected. Colt’s price\/performance ratio is extremely attractive for both national and multinational solutions. If you have any further questions or require more information about SIP trunk, please do not hesitate to contact us!<\/p>\n\n\n\n
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Book a consultation<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n
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$\"Frank$ <\/figure>\n<\/div>\n\n\n\n
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Written by<\/p>\n\n\n\n
Frank Frommknecht<\/h3>\n\n\n\n
Key Account Consultant, SAVECALL<\/strong><\/p>\n\n\n\n
Has supported companies for over 20 years in selecting and optimizing their connectivity solutions. His focus: making complex telecommunications understandable from the customer\u2019s perspective and finding the right solution strategically.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n
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Why<\/h2>\n\n\n\n
$\"\"$ <\/figure>\n<\/div>\n<\/div>\n\n\n\n
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Telecom & IT sourcing. Worldwide. Carrier-independent.<\/h3>\n\n\n\n
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Selection & operation of worldwide connectivity & cloud infrastructure. Without vendor risk & unnecessary costs.<\/p>\n\n\n\n
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80+ carriers worldwide<\/li>\n\n\n\n
One point of contact<\/li>\n\n\n\n
One SLA<\/li>\n\n\n\n
One portal: mySAVECALL<\/li>\n\n\n\n
Min. 20% savings<\/li>\n<\/ul>\n<\/div>\n\n\n\n
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Book a consultation<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n
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25+
years of experience<\/h2>\n<\/div>\n\n\n\n
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Learn more<\/a><\/h5>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n
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40+
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80+
Partner<\/h2>\n<\/div>\n\n\n\n
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Learn more<\/a><\/h5>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n
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1400+ Clients<\/h2>\n<\/div>\n\n\n\n
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Learn more<\/a><\/h5>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n
<\/p>\n\n\n
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Sources<\/h3>\n\n\n\n
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Colt Technology Services: ISDN Services \/ Colt Voice Line Datasheet<\/a><\/li>\n\n\n\n
Colt Technology Services: SIP Trunking Product Page<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n\n
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Frequently Asked Questions<\/h2>\n<\/div>\n<\/div>\n\n\n
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Frequently asked questions about Colt SIP Trunking<\/h3>\n\n\n\n
What is a SIP trunk?<\/strong>
A SIP trunk (Session Initiation Protocol trunk) takes over the function of a classic ISDN connection by transmitting telephony over the IP network, in other words via the internet protocol. Instead of individual ISDN lines, voice communication is carried as data packets over an existing or dedicated internet line. This allows classic ISDN to be fully replaced. Companies must either reserve part of their existing internet bandwidth for telephony or connect a separate line for voice transmission.<\/p> <\/div>
What advantages does Colt SIP Trunking offer over classic ISDN?<\/strong>
Colt SIP Trunking supports CLIP, CLIR and encrypted voice transmission via TLS and SRTP, can be connected via Colt’s own network, IP VPN, Ethernet Private Network or a third-party provider, and allows flat-rate or per-minute billing per channel. It also offers central, Europe-wide uniform management of all locations. Compared with classic ISDN, this provides more flexibility in scaling, billing and connectivity, with full functionality including caller ID transmission, suppression and call barring.<\/p> <\/div>
What determines the cost of a Colt SIP Trunk?<\/strong>
The cost of a Colt SIP Trunk depends on three factors: the billing model for minute packages (usage-based or flat rate per channel), the required bandwidth, where the rule of thumb is 100 kbit\/s per simultaneous call, and one-off migration costs. These migration costs can be reduced through a smooth, gradual changeover. New hardware such as a softphone solution is generally significantly cheaper than existing ISDN hardware.<\/p> <\/div>
How does a smooth migration from ISDN to All IP work?<\/strong>
In a smooth migration, the carrier’s backbone is prepared first. All voice traffic then already runs over the IP network, while the company’s existing ISDN hardware continues operating for the time being. This allows individual sites to be switched completely to IP one by one, for example through the hybrid integration of softphones, while other sites can keep using ISDN until their phone system is fully written off.<\/p> <\/div>
What regulatory requirements does Colt SIP Trunking meet?<\/strong>
Colt SIP Trunking meets common legal and regulatory requirements for voice services, including emergency call routing, government monitoring regulations and data security. This is complemented by standard functions such as phone number management, porting of local numbers, direct extension dialling and call control. This means the service meets the requirements companies expect from a regulated phone connection while remaining compatible with existing telecommunications compliance rules.<\/p> <\/div>
How much bandwidth does a company need for SIP trunking?<\/strong>
As a rule of thumb, 100 kbit\/s of bandwidth is needed per simultaneous call. So if 10 employees are typically on the phone at the same time, around 1 Mbit\/s of internet bandwidth is required. The actual requirement depends on the number of parallel calls within the company and should be factored into the choice of internet connection so that voice quality and other data applications do not compete with each other.<\/p> <\/div> <\/div>\n\n\n
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