Business Communications & AI Glossary | NFON [Contact](# "Contact") ![](/web-assets/f/290788/40x40/d98615a3ea/nfon-sales-contact.svg) Sales & General * [Talk to Sales](tel:+498000636624) * [Write to us](/en/request-information) Search * [![Products](https://a.storyblok.com/f/290788/40x40/539cd331b9/nfon-products.svg) Products](#) Call & Work ![AI icon](/assets/ai_icon.webp) + [Cloud Telephony](/en/products/cloud-telephony/) + [SIP Trunk](/en/products/enablement/) + [Devices](/en/products/devices) Build & Automate ![AI icon](/assets/ai_icon.webp) + [Assistants](/en/products/ai/assistants) + [Bots](/en/products/ai/bots) + [AI Agent Studio](/en/products/ai/agent-studio) Engage & Support ![AI icon](/assets/ai_icon.webp) + [Contact Center](/en/products/customer-contact/) Integrations & Add ons + [Integrations & Add ons](/en/integrations/) * [![Solutions](https://a.storyblok.com/f/290788/40x40/da156cbbb8/nfon-solutions-industries.svg) Solutions](#) Industries + [Health & Wellness](/en/solutions/health-wellness) + [Retail & E-Commerce](/en/solutions/retail) + [Finance & Legal](/en/solutions/finance-insurance) + [Travel & Hospitality](/en/solutions/hospitality) + [Public Sector](/en/solutions/public-sector) + [Energy](/en/solutions/energy) Success stories + [Customer Stories](/en/customer-stories/) * [![Partnerships](https://a.storyblok.com/f/290788/36x36/7bd105c67d/nfon-partner.svg) Partnerships](#) Partner with NFON + [Become a partner](/en/partner/become-partner) + [NGAGE](/en/partner/partner-programme) Partner Portal + [Partner Portal](https://partners.nfon.com/) * [![Help Centre](https://a.storyblok.com/f/290788/40x40/d01fbb4f30/help-nfon.svg) Help Centre](/en/help-center) * [Login](https://start.cloudya.com/ "Login") * International + [International](/en/get-started/cloud-telephony/lexicon) + [Deutschland](/de/los-gehts/cloud-telephonie/lexikon) + [España](/es/get-started/cloud-telephony/lexicon) + [France](/fr/get-started/cloud-telephony/lexicon) + [Italia](/it/get-started/cloud-telephony/lexicon) + [Österreich](/at/los-gehts/cloud-telephonie/lexikon) + [Polska](/pl/get-started/cloud-telephony/lexicon) + [Portugal](/pt) + [United Kingdom](/gb/get-started/cloud-telephony/lexicon) [![NFON Logo](/assets/logo-nfon.svg)](/en/ "NFON Home") * [Products](#) ![](/web-assets/f/290788/36x36/a9f3ceed6f/nfon-call-work.svg) Call & Work ![AI icon](/assets/ai_icon.webp) Seamless communication ![](/web-assets/f/290788/36x36/d03c61cf40/nfon-build-automate.svg) Build & Automate ![AI icon](/assets/ai_icon.webp) AI Automation ![](/web-assets/f/290788/36x36/106823b73b/nfon-engage-support.svg) Engage & Support ![AI icon](/assets/ai_icon.webp) Omnichannel support ![](/web-assets/f/290788/36x36/50b60f5411/nfon-integrations-add-ons.svg) Integrations & Add ons Connect Teams & CRMs + [![](/images/products-call-work-cloudteleophny-navbar-int_Fjf8b.webp) ### Cloud Telephony ![AI icon](/assets/ai_icon.webp) Seamless cloud telephony for every device. High-fidelity audio with European-grade security.](/en/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.](/en/products/enablement/) + [![](/images/products-call-work-devices-navbar-int_Z2dP6.webp) ### Devices Professional telephones and hardware designed for clear calls and all-day comfort.](/en/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.](/en/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.](/en/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.](/en/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.](/en/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.](/en/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.](/en/solutions/health-wellness) + [![](/images/solutions-retail-ecommerce-navbar-int_zUgjw.webp) ### Retail & E-Commerce Connected communication for modern retail and customer engagement.](/en/solutions/retail) + [![](/images/solutions-finance-legal-navbar-int_1Dy5Ax.webp) ### Finance & Legal Trusted communication for regulated and security-conscious organizations.](/en/solutions/finance-insurance) + [![](/images/solutions-hospitality-travel-navbar-int_17WoBe.webp) ### Travel & Hospitality Seamless communication for exceptional guest experiences and service.](/en/solutions/hospitality) + [![](/images/solutions-publicsector-navbar-int_YyABB.webp) ### Public Sector Reliable communication for responsive public services and citizen support.](/en/solutions/public-sector) + [![](/images/solutions-energy-navbar_FDoix.webp) ### Energy Reliable communication for responsive customer service, even during outages and peak demand.](/en/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.](/en/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) ### Become a partner From onboarding to co-branded marketing, we provide the tools you need to win.](/en/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.](/en/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 Centre](/en/help-center) * Search * [Login](https://start.cloudya.com/ "Login") * en + [International](/en/get-started/cloud-telephony/lexicon) + [Deutschland](/de/los-gehts/cloud-telephonie/lexikon) + [España](/es/get-started/cloud-telephony/lexicon) + [France](/fr/get-started/cloud-telephony/lexicon) + [Italia](/it/get-started/cloud-telephony/lexicon) + [Österreich](/at/los-gehts/cloud-telephonie/lexikon) + [Polska](/pl/get-started/cloud-telephony/lexicon) + [Portugal](/pt) + [United Kingdom](/gb/get-started/cloud-telephony/lexicon) * [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. [+49 8000 – 63 66 24](tel:+498000636624 "+49 8000 – 63 66 24
") ![](/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](/en/request-information "Write to us") # Business Communications & AI Glossary Explore key terms, technologies and concepts shaping modern business communications. From cloud telephony and call management to artificial intelligence, automation and data security, this glossary provides clear explanations to help you understand the technologies behind connected, intelligent communication. [Visit the NFON Help Centre](/en/help-center "Visit the NFON Help Centre") ## AI in Business Communications Artificial intelligence is transforming business communications by helping organisations automate conversations, support employees and customers, and make better use of information. Explore key AI concepts, technologies and applications, from AI assistants, chatbots and voicebots to autonomous agents, automation and responsible AI. [AI Assistants vs Chatbots vs AI Agents](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ai-assistants-vs-chatbots-vs-ai-agents) [Conversational AI](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/conversational-ai) [Voice AI and Voicebots](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-ai-voicebots) ## Cloud Telephone System What is a cloud phone system and what technologies power it? This section provides an introduction to the basics of IP-based telephony and explains key technical terms that are relevant when setting up and using a cloud phone system. [a/b Interface](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/a-b-interface) [Asymmetric Digital Subscriber Line (ADSL)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/adsl) [Broadband Internet Connection](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/broadband-internet-connection) [Busy Lamp Field (BLF)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/busy-lamp-field-blf) [Carrier Point-to-Point (CP2P) Connection](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/cp2p) [Cloud](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/cloud) [Direct Data Link (DDL)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ddl) [Download speed](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/download-speed) [Dynamic Circuit Network (DCN)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/dcn) [eFax: Send faxes over the internet](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/efax) [Gateways](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/gateways) [HD telephony](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/hd-telephony) [Internet Connection](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/internet-connection) [Internet telephony](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/internet-telephony) [IP address](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ip-address) [IP DECT](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ip-dect) [IP Multimedia Subsystem (IMS)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ims) [IP phone](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ip-phone) [IP-Centrex](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ip-centrex) [Migration](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/migration) [National & international phone numbers](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/national-international-phone-numbers) [P2P (Point-to-Point Connection)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/p2p) [Quality of Service (QoS)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/qos) [Real-time Transport Protocol (RTP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/rtp) [Request for Comments (RFC)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/request-for-comments-rfc) [SDSL / SHDSL](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sdsl-shdsl) [Session Initiation Protocol (SIP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sip) [SIP-Trunk](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sip-trunk) [Softphones](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/softphones) [Source based call forwarding](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/source-based-call-forwarding) [TCP/IP](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/tcp-ip) [Telecommuting](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telecommuting) [Telephony Application Programming Interface (TAPI)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/tapi) [The Ultimate Questionnaire for Choosing a Cloud Telephony Service Provider](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/the-ultimate-questionnaire-for-choosing-a-cloud-telephony-service-provider) [Virtual fax machine](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/virtual-fax-machine) [Voice over Internet Protocol (VoIP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-over-ip) ## Call Management Effective call management is essential for delivering professional customer service. From call routing and queuing to voicemail and conferencing, this area explains the building blocks of professional call handling. [Address Book](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/address-book) [Asynchronous Transfer Mode (ATM)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/atm) [Call blocking](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-blocking) [Call handling](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-handling) [Call history](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-history) [Call management](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-management) [Call pick up](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-pick-up) [Call profile](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-profile) [Call queueing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-queueing) [Call routing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-routing) [Call Waiting Function](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-waiting-function) [Callback](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/callback) [Calling Line Identification Presentation (CLIP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/clip) [Calling Line Identification Restriction (CLIR)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/clir) [Completion of Calls to Busy Subscriber (CCBS)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ccbs) [Conference call](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/conference-call) [Conference function](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/conference-function) [Dial plan](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/dial-plan) [Direct Calling](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/direct-calling) [Holding calls](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/holding-calls) [Interactive Voice Response (IVR)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ivr) [Music on hold](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/music-on-hold) [Simultaneous ring](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/simultaneous-ring) [Soundstation](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/soundstation) [Telephone number block](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telephone-number-block) [Telephone operator workstation](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telephone-operator-workstation) [Toggling](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/toggling) [Unified Messaging System](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/unified-messaging-system) [Voice encryption](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-encryption) [Voice portals](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-portals) [Voicemail](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voicemail) ## Features Cloud phone systems offer much more than just voice calls. Here you will find helpful features such as plug & play, fax-to-mail, and speed dial explained, all designed to simplify your daily work routine. [Advanced Audio Distribution Profile (A2DP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/a2dp) [Answering machine](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/answering-machine) [AT commands](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/at-commands) [Audio compression](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/audio-compression) [CCNR](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/ccnr) [Fallback](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/fallback) [Fax2Mail](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/fax2mail) [Intercom](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/intercom) [Key assignment](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/key-assignment) [Keypad expansion](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/keypad-expansion) [Multiphone function](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/multiphone-function) [Multiplex connections](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/multiplex-connections) [Plug & Play](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/plug-play) [Redial button](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/redial-button) [Software as a Service (SaaS)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/software-as-a-service) [Sound waves](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sound-waves) [Speed Dial Button](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/speed-dial-button) [Telephone number portability](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telephone-number-portability) [TPS](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/tps) [Uninterruptible Power Supply](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/uninterruptible-power-supply) [Upload speed](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/upload-speed) [Wideband Audio](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/wideband-audio) ## Data Security Data security plays a central role in IP telephony. In the following, you will find the most important terms and technologies related to encryption, data protection, and security standards in cloud communication. [Advanced Encryption Standard (AES)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/aes) [Data encryption](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/data-encryption) [Data Privacy: How Secure Are Cloud Communications Services?](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/data-privacy-how-secure-are-cloud-communications-services) [Firewall](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/firewall) [Firmware](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/firmware) [Key-length](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/key-length) [Security certifications](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/security-certifications) [Servers](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/servers) [WPA2](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/wpa2) ## Customer Management Modern phone systems can often be integrated with CRM platforms and offer tools for customer management. This section provides an overview of the key terms in this area. [Agent](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/agent) [Call Center Monitoring](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-centre-monitoring) [Call centre](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/call-centre) [Customer Relationship Management (CRM)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/customer-relationship-management) [Premium rate numbers](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/premium-rate-numbers) ## Telephone Systems What telephone systems are actually available and how do they differ? In the following, we explain the different system types, including their typical areas of application. [Analogue telephone lines](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/analogue-telephone-lines) [Dedicated line](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/dedicated-line) [Hosted PBX](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/hosted-pbx) [Hybrid telephone system](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/hybrid-telephone-system) [Private Automatic Branch Exchange (PABX)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/pabx) [Private Branch Exchange (PBX)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/private-branch-exchange-pbx) [TC systems](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/tc-systems) [Telephone Connection](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telephone-connection) [Telephone provider](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telephone-provider) ## Wireless Communication Learn more about wireless communication methods used in cloud telephony environments. This includes technologies like DECT, Bluetooth, and other cordless options for flexible setups. [Bandwidth](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/bandwidth) [Bluetooth](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/bluetooth) [Cordless telephony](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/cordless-telephony) [DECT](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/dect) [Multi Cell DECT](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/multi-cell-dect) [SBC Codec](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sbc-codec) [Single Cell DECT](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/single-cell-dect) ## Telecommunications Billing This area explains how billing works in cloud and traditional telecom services. From flat rates to itemized billing, it covers the key concepts that help businesses manage expenses. [Billing units](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/billing-units) [Cheap phone calls: 3 cost-efficient opportunities](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/cheap-phone-calls) [Flat rate](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/flat-rate) [Itemised billing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/itemised-billing) ## Telecommunications Network For IP telephony to work, stable networks are necessary. This section explains how telephone networks are structured, from ISDN and PSTN to mobile networks and VPNs. [Fixed-line network](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/the-fixed-line-network) [Integrated Services Digital Network (ISDN)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/isdn) [ISDN private branch exchange line group](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/isdn-private-branch-exchange-line-group) [Mobile phone network](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/mobile-phone-network) [Primary Rate Interface (PRI)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/primary-rate-interface-pri) [Public Switched Telephone Network (PSTN)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/pstn) [S0 bus](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/s0-bus) [SP2P](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sp2p) [Telecommunication networks](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/telecommunication-networks) [Virtual Private Network (VPN)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/virtual-private-network) [XCAPI](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/xcapi) ## Routing Routing determines how calls are forwarded within a network or company. Here you will learn more about important terms and procedures in the routing of voice data. [Inbound](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/inbound) [Least Cost Routing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/least-cost-routing) [Outbound](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/outbound) [Routing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/routing) ## Connection Technology Various technical processes are also used to create connections. Below you will find brief explanations of methods such as pulse dialing and SDH. [Pulse dialing](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/pulse-dialing) [Synchronous Digital Hierarchy (SDH)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/sdh) [TAE Socket](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/tae-socket) ![NFON Logo](/assets/logo-nfon.svg) News * [Events](https://www.nfon.com/en/news/events) * [Press](https://corporate.nfon.com/en/communication/) Customers * [Cloudya Login](https://start.cloudya.com/auth/login) * [Admin Portal](https://admin.nfon.com/) * [NFON Status](https://status.nfon.com/) About NFON * [Corporate](https://corporate.nfon.com/en/) * [Investor Relations](https://corporate.nfon.com/en/investor-relations/ir-at-a-glance/) * [Sustainability & ESG](https://corporate.nfon.com/en/sustainability/) * [Career](https://corporate.nfon.com/en/careers/) Legal * [GTC-SLA](/en/legal/gtc-sla) * [Legal Notice](/en/legal/legal-notice) * [Trust Center](https://www.nfon.com/en/trust-center/) * [Data Protection](/en/legal/data-protection) * [Cookie Settings](javascript:onclick=UC_UI.showSecondLayer()) © 2026 - NFON | All rights reserved.