Quality of Service (QoS) | NFON Knowledge Base [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/knowledge-base-detail/qos) + [Deutschland](/de) + [España](/es) + [France](/fr) + [Italia](/it) + [Österreich](/at) + [Polska](/pl) + [Portugal](/pt) + [United Kingdom](/gb) [![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/knowledge-base-detail/qos) + [Deutschland](/de) + [España](/es) + [France](/fr) + [Italia](/it) + [Österreich](/at) + [Polska](/pl) + [Portugal](/pt) + [United Kingdom](/gb) * [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") ### Quality of Service (QoS) [Quality of Service in IP networks](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/qos#section-3) [QoS requirements in Voice-over-IP telephony](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/qos#section-4) The acronym QoS stands for the technical term "Quality of Service". QoS defines specific quality requirements which must be met to use a communication service with the desired quality from the subscriber’s perspective. In order to meet these requirements, different actions, parameters and processes are defined depending on the network used or the transfer method, summarised under the term QoS. One can essentially distinguish between the transmission quality and the traffic quality. Whilst the traffic quality primarily pertains to the transmission technology and establishing the connection, the transmission quality pertains to the actual information transfer over a network. ### Quality of Service in IP networks Unlike conventional circuit-switched telephone networks, IP networks are packet-oriented. In order to use these networks to transmit time-sensitive services, there are special requirements with respect to Quality of Service. The key parameters describing the service quality of an IP network are latency, jitter and the packet loss rate. Latency refers to the a packet’s delay which occurs end-to-end during transmission. Jitter measures how much latency deviates from a mean. Lastly, the packet loss rate specifies the percentage of IP packets lost during transmission. ### QoS requirements in Voice-over-IP telephony [Voice-over-IP telephony (VoIP telephony)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-over-ip) is a time-sensitive service with specific QoS requirements for the transmitting network. Voice can only be transmitted in a high quality if these requirements are met. To operate telephone systems via IP network or use the services of a [cloud telephone system](/en/products/cloudya), it is necessary to first verify whether the network is able to provide the required quality of service. Transmission delay and the packet loss rate are particularly key in assessing voice quality. Whilst the loss of individual packets or delays under 100 milliseconds are hardly noticeable by the human ear, high loss rates or delays can result in high communication interference. To ensure the networks are able to meet the QoS requirements, they feature mechanisms to give priority to certain IP packets (voice packets) and delay others. ### Related Articles ### Voice over Internet Protocol (VoIP) PSTN stands for Public Switched Telephone Network and is generally known as the traditional phone network. It has been connecting people since the late 19th century, at first over copper telephone lines and later using fibre optic cables, satellites, and undersea cables. All of these are interconnected by switching centres which establish a dedicated connection – or circuit – between callers. Voice signals can then travel over this circuit. When the caller speaks into his handset, the caller’s phone translates the sound waves into electrical signals. These are transmitted over the PSTN (converted to optical signals for part of the way, so they can travel via fibre optic cables), and the phone at the other end of the line then translates the received signals back into sound. The arrival of **Voice over IP (VoIP)** technology – essentially, transmitting voice calls over the Internet rather than the PSTN – challenged traditional telephony and fundamentally changed how people communicate. [Voice over Internet Protocol (VoIP)](/en/get-started/cloud-telephony/lexicon/knowledge-base-detail/voice-over-ip) [Back](#) ![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.