SIP Trunks

Firstcom SIP trunks are the successor to ISDN30

SIP trunking

SIP (or Session Internet Protocol) allows calls to be made from PBXs via VoIP (Voice over Internet Protocol). Connect your IP PBX to the heart of our network and enjoy a flexible, cost effective alternative to ISDN.

Service driven businesses can create a local presence by using virtual numbers with a local area code with your SIP. Multi-site organisations requiring one centralised solution can administer their complete network operation from one location. In the UK businesses must change from their ISDN services by 2025 when this technology will be switched off.

Who should consider SIP trunking?

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Why engage with us?

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SIP Encrypt

The General Data Protection Regulation levies significant fines for businesses which fail to protect their data. If you transmit personal data over the telephone you should take steps to encrypt this as part of your overall data protection exercise.

We understand call security and can help you take care of this as part of your journey towards compliance and best practice.

Wiretap proof VoIP

If you are deploying an internet based telephony solution using an IP PBX  or unified communications, then you should consider adding call encryption. When the public internet or even private MPLS lines are used to make and receive calls, there is a risk that these calls can be hacked.

Firstcom’s encrypted SIP service is a fully audited secure VoIP solution that safeguards against eavesdropping and toll fraud. This service is essential if you accept credit card payments over the phone or if you handle confidential information. Call encryption is crucial for contact centres, the legal and financial sector, and pharmaceutical firms.

Information security

Calls made over the internet are vulnerable to malicious hackers. If you transmit sensitive information over the phone, you could become the victim of intellectual property theft. If you are compliance driven or have an information security policy in place, you need to protect your business communications from the risk of remote access wiretapping.


All organisations, no matter how small, deal with sensitive data relating to their stakeholders. These can be customers, partners, suppliers, employees, or investors. If you don’t take measures to prevent this data from falling into the wrong hands, then you risk damage to your reputation at the very least. And you may end up being fined.

The General Data Protection Regulation

The General Data Protection Regulation (GDPR) came into force in May 2018 and mandates significant fines for businesses that fail to protect the data they hold. If you transmit personal data by telephone, adding call encryption will help you to comply with GDPR.

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Discover the benefits of secure SIP

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