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High-fidelity audio with European-grade security.](/gb/products/cloud-telephony/) + [![](/images/products-call-work-siptrunk-navbar-int_ZH5NzW.webp) ### SIP Trunk Secure cloud connectivity for your existing hardware. Scales instantly with your business.](/gb/products/enablement/) + [![](/images/products-call-work-devices-navbar-int_Z2dP6.webp) ### Devices Professional telephones and hardware designed for clear calls and all-day comfort.](/gb/products/devices) + [![](/images/products-build-automate-assistants-navbar-int_2ghUIJ.webp) ### Assistants ![AI icon](/assets/ai_icon.webp) Pre-configured, plug-and-play digital roles like FrontDesk and Workdesk. Ready to deploy instantly with zero coding required.](/gb/products/ai/assistants) + [![](/images/products-build-automate-bots-navbar-int_Z1p57Vm.webp) ### Bots ![AI icon](/assets/ai_icon.webp) Prompt-driven, multi-channel conversational experiences. Automate custom customer journeys across Web Chat, Voice, and Livechat.](/gb/products/ai/bots) + [![A chatbot creation interface is shown with a readiness message, build report, agent prompt details, and created tools list, over a gradient background.](/images/products-build-agent-studio-navbar-int_Z1Y88dE.webp) ### AI Agent Studio ![AI icon](/assets/ai_icon.webp) Simply turn your ideas into AI agents for your business. Describe the task, create a working agent, then optimize it in one workspace.](/gb/products/ai/agent-studio) + [![](/images/products-engage-support-navbar-int_1xyFBE.webp) ### Contact Center ![AI icon](/assets/ai_icon.webp) Omnichannel customer service for modern teams. Manage conversations, automation, AI assistance, and customer context.](/gb/products/customer-contact/) + [![](/images/products-integrations-addons-navbar-int_Z1Ka5ea.webp) ### Integrations & Add ons Expand your capabilities and natively connect your everyday business to keep all workflows unified.](/gb/integrations/) * [Solutions](#) ![](/web-assets/f/290788/40x40/da156cbbb8/nfon-solutions-industries.svg) Industries Tailored solutions ![](/web-assets/f/290788/40x40/155f2a989d/nfon-success.svg) Success stories 54,000+ trust us + [![](/images/solutions-health-wellness-navbar-int_Z15q3kJ.webp) ### Health & Wellness Secure communication for better patient experiences and care delivery.](/gb/solutions/health-wellness) + [![](/images/solutions-retail-ecommerce-navbar-int_zUgjw.webp) ### Retail & E-Commerce Connected communication for modern retail and customer engagement.](/gb/solutions/retail) + [![](/images/solutions-finance-legal-navbar-int_1Dy5Ax.webp) ### Finance & Legal Trusted communication for regulated and security-conscious organizations.](/gb/solutions/finance-insurance) + [![](/images/solutions-hospitality-travel-navbar-int_17WoBe.webp) ### Travel & Hospitality Seamless communication for exceptional guest experiences and service.](/gb/solutions/hospitality) + [![](/images/solutions-publicsector-navbar-int_YyABB.webp) ### Public Sector Reliable communication for responsive public services and citizen support.](/gb/solutions/public-sector) + [![](/images/solutions-energy-navbar_FDoix.webp) ### Energy Reliable communication for responsive customer service, even during outages and peak demand.](/gb/solutions/energy) + [![](/images/solutions-costumerstroy-navbar-int_Z1MdOsM.webp) ### Customer Stories Real-world impact across every industry. Explore how we solve complex communication challenges for Europe’s leading brands.](/gb/customer-stories/) * [Partnerships](#) ![](/web-assets/f/290788/36x36/7bd105c67d/nfon-partner.svg) Partner with NFON Join the NFON network ![](/web-assets/f/290788/36x36/8c5c9a9c78/nfon-partner-portal.svg) Partner Portal Existing partner login + [![](/images/partnerships-partner-navbar-int_ZHYGKx.webp) ### Partner From onboarding to co-branded marketing, we provide the tools you need to win.](/gb/partner/become-partner) + [![](/images/partnerships-ngage-navbar-int_Zs3yY9.webp) ### NGAGE Discover our tiered rewards system designed to help you scale your business and revenue.](/gb/partner/partner-programme) + [![](/images/partnerships-partnerportal-navbar-int_2ki451.webp) ### Partner Portal Access partner tools, deal registration, training resources, and program benefits in one place.](https://partners.nfon.com/) * [Help Center](/gb/help-centre) * Search * [Login](https://start.cloudya.com/ "Login") * gb + [International](/en/products/enablement/sip-trunk-flexx) + [Deutschland](/de/produkte/enablement/sip-trunk-flexx) + [España](/es/productos/enablement/sip-trunk-flexx) + [France](/fr/produits/enablement/sip-trunk-flexx) + [Italia](/it/servizi/connessione-cloud/sip-trunk-flexx) + [Österreich](/at/produkte/enablement/sip-trunk-flexx) + [Polska](/pl/produkty/enablement/sip-trunk-flexx) + [Portugal](/pt/produtos/enablement/sip-trunk-flexx) + [United Kingdom](/gb/products/enablement/sip-trunk-flexx) * [Contact](#) [Contact](# "Contact") + ![](/web-assets/f/290788/40x40/d98615a3ea/nfon-sales-contact.svg) Sales & General Get in touch with us. ![](/images/getstarted-talktosales-navbar-int_ZMspQ4.webp) ### Talk to Sales Get a free consultation to see how NFON products can meet your needs. [+44 330 383 8000](tel:+443303838000 "+44 330 383 8000") ![](/images/getstarted-writetous-navbar-int_ZY7MOf.webp) ### Write to us Fill out our request form. Our experts will respond as soon as possible. [Write to us](/gb/request-information "Write to us") PRODUCT SPECIFICATIONS # SIP Trunking. Modern telephony. Built on what you already have. Modernise your telephony without replacing existing infrastructure. Manage numbers centrally, stay reachable during peak demand, and scale communication as your business grows. [Get in touch](/gb/request-information "Get in touch") [Access SIP Trunk Flexx demo](https://nfon.navattic.com/u020fr3 "Access SIP Trunk Flexx demo") ![NFON SIP Trunk interface displaying number routing, phone numbers, and conference editing options on a gradient blue-green background.](/images/sip-productdetialpage-hero-international_Z2m9pmM.webp) ![NFON SIP Trunk interface displaying number routing, phone numbers, and conference editing options on a gradient blue-green background.](/images/sip-productdetialpage-hero-international_1AyVfD.webp) Integrated. Secure. Reliable ## The standard for secure connectivity. ![](/images/gdpr-badge_1eKxN4.webp) ![](/images/nfon-c5-attestation_2kWV2H.svg) ![](/images/connect-professional-poty_ZosOlt.svg) ![](/images/nfon-capterra-5-sip_23DOO4.svg) ENGINEERED STANDARDS ## Core capabilities of the NFON SIP Trunk foundation. Beyond simple connectivity, NFON SIP Trunk provides the technical foundation for enterprise voice. Every trunk is built with high-fidelity security, geo-redundant resilience, and modular scalability as standard. ### Flexible number routing Distribute phone numbers across multiple trunk lines without purchasing new number blocks, giving you more flexibility and control over your communication setup. ### Flexible plans & add-ons Choose the telephony features, integrations, and add ons your business actually needs, with the flexibility to scale communication as you grow. ### Extend existing phone systems Connect IP telephony to your existing PBX infrastructure while keeping your current phone numbers and communication setup fully operational. ### Centralised European connectivity Manage communication across multiple locations through one central portal with reliable European connectivity and local support. ### Call blocking Block outgoing calls to selected destinations for enhanced security. ### Fraud detection System-controlled monitoring helps detect unusual call-cost patterns and protect your trunk from misuse. ### High availability Connect a second PBX for redundancy and even call load distribution across different locations. ### Backup systems Ensure constant coverage with backup systems that kick in when your PBX is unavailable. ### Self-service portals Set up and manage your SIP trunks confidently with everything at your fingertips. ### Conference services Host audio conferences with up to 50 participants easily. ### Genesys Cloud / Contact Center Integration Enable PSTN connectivity for your contact center with minbound and outbound calling. ### Microsoft Teams\* Integration Connect Microsoft Teams\* with PSTN and standard telephony features via Operator Connect or Direct Routing. [Book a non-binding consultation](/gb/request-information "Book a non-binding consultation") TECHNICAL DOCUMENTATION ## Discover more. [NFON SIP Trunk One-pager](/web-assets/f/290788/62060b0483/sip_trunk_flexx_onepager_en_2024-07.pdf) [NFON SIP Trunk Product Sheet](/web-assets/f/290788/7d870fe914/en_nconnect_voice_product_sheet_2022-06.pdf) [ISO 27001 Certificate](/web-assets/f/290788/x/7bab6c1c54/iso_iec_27001_2022.pdf) INFRASTRUCTURE MAPPING ## Is NFON SIP Trunk right for you? COMPLEX TOPOLOGY ### Businesses with complex infrastructure. Ideal for organisations managing multiple locations or disparate PBX systems that require a single, unified link without moving fully to the cloud. LEGACY HYBRID ### Enterprises with on-premise systems. Organisations looking to integrate cloud benefits and high-end security features without replacing existing physical hardware investments. OPEX EFFICIENCY ### Cost-conscious companies. Businesses aiming to eliminate wasteful ISDN overhead and move to a transparent, pay-per-channel model that scales with actual usage. DISTRIBUTED WORKFORCE ### Global teams. Enterprises with international branches or remote teams requiring reliable, unified connectivity and carrier-grade voice quality across borders. [Access SIP Trunk demo](https://nfon.navattic.com/u020fr3 "Access SIP Trunk demo") FInd out what our customers think about nfon ## See how others are succeeding with NFON. > "Instead of having different PBX systems for each location, we can now use one single, easily scalable communication solution. The integration of Cloudya has given our teams a lot more flexibility." ![](/web-assets/f/290788/1206x1560/1ede4b4a5f/demeter.png) Tobias Armleder IT Lead, Demeter > “Since we switched to NFON, we can finally > take calls wherever we are and from any > device. The integrations with Microsoft > Teams have made things a lot easier, and > we can use the whole Microsoft Teams > suite, with any client or partner - just being > a click away at all times.” ![](/web-assets/f/290788/1206x1560/ddd13429d6/untitled-design-31.png) Jeanne Beck, Marketing Manager, Wefapress > Our biggest challenge is to stay connected at all times. Thanks to Cloudya’s seamless integration with Microsoft Teams, we can now make calls directly from the app and benefit from streamlined workflows and insightful reporting with Nmonitoring Queues.” ![](/web-assets/f/290788/200x200/eec7d21fa5/financial_com_logo.jpeg) Fritz Pschormeir Head of IT Infrastructure, financial.com TECHNICAL REFERENCE ### The SIP Infrastructure Lexicon. ## Direct Routing. The technology that connects Microsoft Teams to the global phone network via your SIP Trunk. ## PSTN Connectivity. Public Switched Telephone Network—the traditional network your digital trunk bridges into. ## PBX Endpoint. The physical or virtual "terminal" where your internal phone logic lives. ## Number Porting. The secure process of moving your existing DDIs from a legacy provider to the NFON cloud. ## Frequently asked questions (FAQ). #### What is NFON SIP Trunk? SIP stands for Session Initiation Protocol. NFON SIP Trunk is a VoIP telephony solution that makes your existing telephone system IP-enabled. It connects your telephone system to the public telephone network via the internet. This provides you with flexible scalability, easy integration, high availability, and low telephone costs. Multiple telephone systems and endpoints can be managed under a single SIP trunk, including Microsoft Teams integration. #### Do I need new hardware to use SIP Trunk? No, SIP Trunk integrates with your existing PBX systems and supports on-premise connectivity. #### Is customer support available? Absolutely, our support team is available 24/7 to assist you. #### How much does NFON SIP Trunk cost? All prices can be found **[here](/en/pricing)**. Please note that these prices are only valid for Germany and prices vary across countries. #### How can I port my phone number to an NFON SIP trunk? You can port (take) your existing phone numbers (MSN) to NFON SIP Trunk if you already use geographic phone numbers with another provider. Learn more at **** #### How does a SIP Trunk work? A SIP trunk is a connection that allows a telephone system to make calls over the internet. It replaces traditional ISDN or analogue lines. Explained briefly and clearly: * Your telephone system (PBX) connects to the SIP provider via the internet. * The connection uses the SIP (Session Initiation Protocol) to establish, control, and terminate calls. * The voice data itself is transmitted as VoIP data packets. * The SIP provider routes calls to the public telephone network or receives incoming calls. #### Can I keep my current phone numbers? Yes, our flexible number routing allows you to retain and assign your existing numbers without purchasing new blocks. #### How does SIP Trunk enhance security? We prioritise security with features like call blocking and fraud detection to protect your communications. #### How many calls are possible per SIP trunk? The maximum number of simultaneous calls per NFON SIP trunk depends on the number of voice channels booked. The XL option allows 50 simultaneous calls. [All packages](/en/pricing "All packages") #### Can I use my mobile phone number for VoIP? A private mobile phone number cannot usually be used directly as a phone number for an NFON SIP trunk. NFON SIP trunks support the use of geographic phone numbers (landline numbers) that are ported or newly assigned. ![](/images/banner-450-x-800-mobile_Z1tqnM1.webp) ![](/images/banner-1440x400_8iM5V.webp) ## Jump into the cloud - upgrade now! 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