> ## Documentation Index > Fetch the complete documentation index at: https://www.vobiz.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # Vobiz Docs Sitemap - Blogs > Every page in the Blogs section of the Vobiz documentation, grouped as it appears in the sidebar, with a one line summary of each. Every page in the **Blogs** section of the Vobiz documentation (55 pages), grouped as it appears in the sidebar, with a one line summary of each. The other sections are listed on the [documentation sitemap](https://www.vobiz.ai/docs/resources/sitemap). ## Blogs * [Vobiz Blog](https://www.vobiz.ai/docs/blogs.md) — Guides, deep-dives, and product updates from the Vobiz team - voice AI engineering, telephony best practices, and platform announcements ## Articles * **Phone numbers** * [What Is a Toll-Free Number? 1800 Numbers in India](https://www.vobiz.ai/docs/blogs/what-is-a-toll-free-number.md) — A toll-free number lets customers call you at no charge while your business pays * [What Is a 140 Phone Number? Why They Call, and 1600 Numbers](https://www.vobiz.ai/docs/blogs/what-is-a-140-number.md) — A 140 phone number is India's series for promotional calls * [Telephone Numbers in India: Every Number Type Explained](https://www.vobiz.ai/docs/blogs/indian-phone-numbers-explained.md) — Telephone numbers in India explained: mobile, landline, 1800, 1860, 140, 1600 and 1601 * [What Is CNAP? Caller Name Display in India Explained](https://www.vobiz.ai/docs/blogs/what-is-cnap.md) — CNAP shows a caller's registered name on Indian phones from November 2026 * [What Is a Landline Number? Meaning, Format & Dialling](https://www.vobiz.ai/docs/blogs/what-is-a-landline-number.md) — A landline number is a fixed-line phone number linked to an area code * [What Is a Virtual Phone Number? Free Options, India Rules](https://www.vobiz.ai/docs/blogs/what-is-a-virtual-phone-number.md) — A virtual phone number works without a SIM or fixed line * [Do Not Call Registry India: How DND and NDNC Work](https://www.vobiz.ai/docs/blogs/what-is-dnd-ndnc-india.md) — India's do not call registry lets you block promotional calls and SMS * [What Is Number Masking? A Call Masking Guide for India](https://www.vobiz.ai/docs/blogs/what-is-number-masking.md) — Number masking, or call masking, connects two people through a proxy number * [What Is a DID Number? Full Form, SIP Routing, India Rules](https://www.vobiz.ai/docs/blogs/what-is-a-did-number.md) — DID stands for Direct Inward Dialing. See how a DID number reaches your system over SIP, how many you need, and which India rules apply to DID blocks * [Phone Number E.164 Format: Rules, India Cases, Validation](https://www.vobiz.ai/docs/blogs/what-is-e164-phone-number-formatting.md) — E.164 writes a phone number as a country code and national number, 15 digits at most * [What Is STIR/SHAKEN? How Carriers Sign Caller ID](https://www.vobiz.ai/docs/blogs/what-is-stir-shaken.md) — STIR/SHAKEN lets carriers sign caller ID so receiving networks can check it * [What Is Caller ID and CNAM? Why Names Fail to Display](https://www.vobiz.ai/docs/blogs/what-is-caller-id-cnam.md) — Caller ID carries the number, and CNAM is a separate name lookup * [Toll-Free vs Local vs Mobile Numbers: Who Pays, Who Answers](https://www.vobiz.ai/docs/blogs/toll-free-vs-local-vs-mobile-numbers.md) — Compare toll-free, local and mobile numbers by who pays, who picks up and what India's rules allow * **IVR** * [IVR Full Form and Meaning: What Is an IVR Call?](https://www.vobiz.ai/docs/blogs/what-is-an-ivr.md) — IVR stands for Interactive Voice Response * [What Is an IVR Number? Meaning, Types and How to Choose](https://www.vobiz.ai/docs/blogs/what-is-an-ivr-number.md) — An IVR number is a phone number answered by an automated menu * [What Is Multi-Level IVR? How to Design One for India](https://www.vobiz.ai/docs/blogs/what-is-multi-level-ivr.md) — Multi-level IVR explained for business owners: how layered phone menus work, how many levels to use, and what TRAI's November 2026 rule means for.. * **Calls and contact centers** * [CDR Full Form: What a Call Detail Record Contains](https://www.vobiz.ai/docs/blogs/what-is-a-call-detail-record.md) — CDR full form in telecom is call detail record: a per-call log of numbers, times, outcome and cost, with no audio * [What Is Call Forwarding? How It Differs From Call Transfer](https://www.vobiz.ai/docs/blogs/what-is-call-forwarding.md) — Call forwarding sends a call to another number before anyone answers * [What Is a Missed Call Service? How Businesses Use It](https://www.vobiz.ai/docs/blogs/what-is-a-missed-call-service.md) — A missed call service turns one unanswered ring into a lead * [What Is Call Tracking? How It Measures Marketing in India](https://www.vobiz.ai/docs/blogs/what-is-call-tracking.md) — Call tracking shows which ad, listing, or page made your phone ring * [AHT Full Form: Average Handle Time and How to Improve It](https://www.vobiz.ai/docs/blogs/what-is-average-handle-time.md) — AHT full form is Average Handle Time. See the formula with a worked example, what counts, how to set a fair target, India factors, and how to improve.. * [Automatic Calls: How Automated Calling and AMD Work](https://www.vobiz.ai/docs/blogs/automated-calling-answering-machine-detection.md) — An automatic call is placed by software, not a person * [What Is Talk Time? Call Center and Recharge Meaning](https://www.vobiz.ai/docs/blogs/what-is-talk-time.md) — Talk time is rupee balance on an Indian recharge and conversation seconds in a call center * [What Is an Auto Dialer? Preview, Progressive, Predictive](https://www.vobiz.ai/docs/blogs/what-is-an-auto-dialer.md) — An auto dialer places calls from a list without manual dialing * [Call Center Optimization with AI: Metrics, Rollout, ROI](https://www.vobiz.ai/docs/blogs/call-center-optimization-with-ai.md) — Call center optimization with AI: which metrics move, where humans stay, how to roll out safely, and a worked ROI example you can rerun with your own.. * [AI Warm Transfer: Build Context-Aware Call Handoffs](https://www.vobiz.ai/docs/blogs/context-aware-call-transfers.md) — An AI warm transfer briefs a human before the caller joins * [Call Recording APIs: Stereo, Consent and India Retention](https://www.vobiz.ai/docs/blogs/call-recording-apis-compliant-pipelines.md) — Design a call recording API pipeline: stereo capture, consent gates, card-data carve-outs, redaction, and retention under India's DPDP, RBI, and SEBI.. * [What Is Answering Machine Detection? Errors, Tuning, India](https://www.vobiz.ai/docs/blogs/what-is-answering-machine-detection.md) — Answering machine detection classifies who picked up an outbound call * [Intelligent Call Escalations: When and How to Hand Off](https://www.vobiz.ai/docs/blogs/intelligent-call-escalations.md) — Intelligent call escalation gets callers to the right person with their story intact * [What Is a Call Leg? A-Leg, B-Leg, SIP and Billing](https://www.vobiz.ai/docs/blogs/what-is-a-call-leg.md) — A call leg is one connection between a voice platform and one party * [What Is Call Routing? Types, Examples and India Rules](https://www.vobiz.ai/docs/blogs/what-is-call-routing.md) — Call routing decides who answers each phone call * **SMS and WhatsApp** * [MMS Meaning: What Is MMS, How It Works and Business Use](https://www.vobiz.ai/docs/blogs/what-is-mms.md) — MMS means Multimedia Messaging Service. Learn how MMS works, what an MMS video is, SMS vs MMS limits, India's TRAI rules, and which channel to choose * [DLT Registration in India: Full Form, Process and Rules](https://www.vobiz.ai/docs/blogs/what-is-dlt-registration.md) — DLT stands for Distributed Ledger Technology * [Bulk Message Sending: What Is Bulk SMS in India?](https://www.vobiz.ai/docs/blogs/what-is-bulk-sms.md) — Bulk SMS sends one message to many people at once * [WhatsApp Marketing: A Practical Guide for Businesses](https://www.vobiz.ai/docs/blogs/whatsapp-marketing-guide.md) — WhatsApp marketing explained for Indian businesses: which tool to pick, consent rules, per-message costs, Meta's sending limits and a 30-day launch.. * [6 number code SMS: short codes vs long codes explained](https://www.vobiz.ai/docs/blogs/sms-short-codes-vs-long-codes.md) — What a 6 number code means in SMS, how short codes and long codes differ, how India's DLT headers change the choice, and how to pick a sender for.. * [WhatsApp Automation: What to Automate and What Not To](https://www.vobiz.ai/docs/blogs/whatsapp-automation-guide.md) — WhatsApp automation for Indian businesses: what to automate, what to leave to people, Meta's latest pricing and limits, consent rules, and how to.. * [Bank SMS Format: OTP and DLT SMS Templates for India](https://www.vobiz.ai/docs/blogs/sms-templates-for-businesses-india.md) — Bank SMS format samples, OTP messages and DLT-ready SMS templates for Indian businesses, with TRAI variable tags, RBI alert fields and approval.. * [Polite Payment Reminder SMS: Samples and How to Send](https://www.vobiz.ai/docs/blogs/payment-reminder-sms.md) — Polite payment reminder SMS samples for every stage, in English and Hindi, plus a send schedule, India DLT rules, and how to send them without spam.. * [What Is OTP SMS? How Mobile Verification Works](https://www.vobiz.ai/docs/blogs/what-is-otp-sms.md) — OTP SMS is a single-use code texted to prove control of a phone number * [What Is A2P 10DLC? US Business Texting Registration](https://www.vobiz.ai/docs/blogs/what-is-a2p-10dlc.md) — A2P 10DLC is the US carrier program for business texts on local numbers * [What Is RCS Messaging? RCS vs SMS for Business](https://www.vobiz.ai/docs/blogs/what-is-rcs-messaging.md) — RCS adds a verified name, images and buttons to the texting app * **VoIP, SIP and voice tech** * [What Is VoIP? Packets, Codecs, Delay and India's Rules](https://www.vobiz.ai/docs/blogs/what-is-voip.md) — VoIP sends calls as IP packets. See how a VoIP call travels, the real bandwidth per codec, delay limits, VoLTE vs VoIP, and what India's telecom.. * [TTS Full Form: How Text-to-Speech Works on Phone Calls](https://www.vobiz.ai/docs/blogs/what-is-text-to-speech.md) — TTS full form is text-to-speech. Learn how engines turn text into audio, why 8 kHz phone lines change the voice, Hindi challenges, and India's A2P.. * [PBX Full Form: What a PBX Does and When You Need One](https://www.vobiz.ai/docs/blogs/what-is-a-pbx.md) — PBX full form is Private Branch Exchange. Learn how a PBX routes calls, EPABX vs IP vs cloud PBX, channel sizing math, India's 2026 rules, and when.. * [What Is SIP Trunking? Channels, Sizing and India Rules](https://www.vobiz.ai/docs/blogs/what-is-sip-trunking.md) — SIP trunking links a PBX or voice app to the PSTN over IP * [What Is a Voice API? Call Lifecycle, Webhooks and Media](https://www.vobiz.ai/docs/blogs/what-is-a-voice-api.md) — A voice API lets software place, answer and control phone calls * [What Is Cloud Telephony? How It Works and India Rules](https://www.vobiz.ai/docs/blogs/what-is-cloud-telephony.md) — Cloud telephony runs your phone system on a provider's servers * [What Is WebRTC? Meaning, How It Works, When to Use It](https://www.vobiz.ai/docs/blogs/what-is-webrtc.md) — WebRTC means real-time audio, video and data in the browser * [What Is a Voice Bot? How AI Voice Agents Handle Calls](https://www.vobiz.ai/docs/blogs/what-is-a-voice-bot.md) — A voice bot holds spoken conversations on phone calls * [What Is SIP? Sessions, the Handshake and Call Failures](https://www.vobiz.ai/docs/blogs/what-is-sip.md) — SIP sets up, changes, and ends calls but never carries the audio * [ASR Transcription: How Speech Becomes Text on Calls](https://www.vobiz.ai/docs/blogs/what-is-voice-transcription-asr.md) — ASR transcription turns speech into text. Learn how it works on phone calls, how to read WER, when 8 kHz matters, and how to test engines on Indian.. * [SIP vs VoIP: Call Layers, Buying Choices and India Rules](https://www.vobiz.ai/docs/blogs/sip-vs-voip.md) — VoIP is the category and SIP is one protocol inside it * [What Is CPaaS? What It Does and When You Need One](https://www.vobiz.ai/docs/blogs/what-is-cpaas.md) — CPaaS lets your software make calls and send SMS or WhatsApp messages without running telecom systems This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.