--- title: Serhii Omelchenko | Telnyx canonical: https://telnyx.com/authors/serhii-omelchenko --- # Serhii Omelchenko | Telnyx Author # Serhii Omelchenko Global AEO/SEO Manager Serhii is Global AEO/SEO Manager at Telnyx, based in Amsterdam, he is focused on making communications infrastructure findable and credible across both traditional search and AI-driven discovery. He previously led SEO and GEO strategy for some of the world’s most recognized consumer brands. 10 Articles 2018 Joined ## Latest articles Everything Serhii has published, most recent first. * [![Laptop terminal controlling a desk phone call](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-what-is-call-control-1.png?width=3600&format=webp)**Voice**16, Oct 2026What is call control? Direct, programmable control over every callWhat is call control? Learn how call control works in a switch, a cloud API and a contact center, and how to transfer calls and stream media with Telnyx.](https://telnyx.com/resources/what-is-call-control) * [![Laptop SIP trace showing 486 Busy Here](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-sip-response-codes-need-know-2-minutes-1.png?width=3600&format=webp)**SIP Trunking**14, Oct 2026SIP response codes: a quick reference to every SIP code and errorSIP response codes, SIP codes and SIP error codes explained in two minutes: the full 1xx to 6xx list, what each code means, and which ones to retry or fix.](https://telnyx.com/resources/sip-response-codes) * [![SMS and MMS messages on a phone](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-sms-vs-mms-1.png?width=3600&format=webp)**Messaging**12, Oct 2026SMS vs MMS Explained for Developers: Limits, Cost and One APISMS vs MMS compared for developers: character limits, media types, cost, when to send each and how to send both with one Telnyx API.](https://telnyx.com/resources/sms-vs-mms) * [![Retail order confirmation on a phone](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-whatsapp-business-retail-illustration.png?width=3600&format=webp)**WhatsApp Business API**8, Oct 2026WhatsApp Business Messaging for Retail: Setup and PricingWhatsApp Business messaging for retail: order updates, promotions and support from one Telnyx number, from $0.004 a message. Setup steps and a sample API call.](https://telnyx.com/resources/whatsapp-business-retail) * [![WhatsApp Business for Hospitality: Guest Messaging, Costs and Setup](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-whatsapp-business-for-hospitality.png?width=3600&format=webp)**WhatsApp Business API**7, Oct 2026WhatsApp Business for Hospitality: Guest Messaging, Costs and SetupWhatsApp Business hospitality guide: how hotels, airlines and venues message guests across the stay, what it costs, and how to run it on one Telnyx number.](https://telnyx.com/resources/whatsapp-business-hospitality) * [![WhatsApp messages with per-message prices](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-whatsapp-business-api-cost-3.png?width=3600&format=webp)**WhatsApp Business API**7, Oct 2026WhatsApp Business API Cost in 2026 After October 1WhatsApp Business API cost in 2026: Meta's per-message rates after October 1, the 1,000 free service messages, BSP markup and a worked Telnyx example.](https://telnyx.com/resources/whatsapp-business-api-cost) * [![IoT devices: which connectivity each device needs and what its data costs a month](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-iot-devices-4.png?width=3600&format=webp)**IoT**2, Oct 2026IoT Devices: Definition, Examples, and How to Connect ThemLearn what IoT devices are, see examples by category, and compare the connectivity each device needs, with cellular data from $0.01 per MB.](https://telnyx.com/resources/iot-devices) * [![white label eSIM reseller purchase API](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-white-label-esim-reseller-black.png?width=3600&format=webp)**Wireless**28, Sep 2026How to launch a white label eSIM reseller businessCompare ways to launch a white label eSIM reseller brand, what each costs to build and run, and how Telnyx eSIM puts your name on the network.](https://telnyx.com/resources/white-label-esim-reseller) * [![SMS Gateways Explained](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/telnyx-sms-gateways-explained-streamline-flow-featured.svg)**Messaging**10, Sep 2026What is an SMS gateway and how does it work?An SMS gateway routes text messages between applications and mobile networks. Learn how SMS gateways work, compare top providers, and integrate with the Telnyx SMS API.](https://telnyx.com/resources/sms-gateway) * [![RCS Business Messaging Pricing featured image](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/featured-rcs-business-messaging-pricing-1.svg)**Messaging**9, Sep 2026RCS Business Messaging Pricing How It Works and What to ExpectRCS business messaging pricing depends on message type, destination, volume, and carrier. Learn how pricing works and what to ask providers before you commit.](https://telnyx.com/resources/rcs-business-messaging-pricing) [Start building](https://telnyx.com/sign-up) ### Ask AI * [![GPT](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/chatgpt_icon-ea55e09d.jpeg?width=92&format=webp)](https://chat.openai.com/?q=What makes Telnyx's global network different, breakdown call quality for normal phone calls and voice AI calls.) * [![Claude](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/claude_icon-c7c8eef3.webp?width=92&format=webp)](https://claude.ai/new?q=What makes Telnyx's global network different, breakdown call quality for normal phone calls and voice AI calls.) * [![Perplexity](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/perplexity_icon-cd5b74f1.webp?width=92&format=webp)](https://www.perplexity.ai/search?q=What makes Telnyx's global network different, breakdown call quality for normal phone calls and voice AI calls.) * [![Gemini](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/gemini_icon-4ff1cbf4.webp?width=92&format=webp)](https://www.google.com/search?udm=50&aep=11&q=What makes Telnyx's global network different, breakdown call quality for normal phone calls and voice AI calls.) * [![Grok](https://d2efw2akbx8gaf.cloudfront.net/https://dotcom-payload-assets-prod.s3.us-east-1.amazonaws.com/cms-media/grok_icon-e588e5bd.webp?width=92&format=webp)](https://x.com/i/grok?text=What makes Telnyx's global network different, breakdown call quality for normal phone calls and voice AI calls.)