---
title: "Discussion on \"What Is a DID Number? Full Form, SIP Routing and Sizing\" | Hashnode"
description: "Discussion on \"What Is a DID Number? Full Form, SIP Routing and Sizing\". Direct Inward Dialing, hop by hop over SIP, plus how to size a DID block"
url: "https://hashnode.com/posts/what-is-a-did-number/6af42785aebd2641c3271e36"
---

[Feed](https://hashnode.com/feed) /

Discussion

# [What Is a DID Number? Full Form, SIP Routing and Sizing](https://piyuzz.hashnode.dev/what-is-a-did-number?utm_source=hashnode&utm_medium=feed)

Direct Inward Dialing, hop by hop over SIP, plus how to size a DID block

1d ago · 13 min read · piyuzz.hashnode.dev  
Read the article

-   [#sip](https://hashnode.com/tag/sip)
-   [#telephony](https://hashnode.com/tag/telephony)
-   [#voip](https://hashnode.com/tag/voip)
-   [#sip-trunking](https://hashnode.com/tag/sip-trunking)
-   [#voice-ai](https://hashnode.com/tag/voice-ai)

## Written by

[Piyush Sahoo](https://hashnode.com/@piyuzz)

@piyuzz · Bengaluru, India

  
[View profile](https://hashnode.com/@piyuzz)

Founding Member, Vobiz. Writing about AI voice agents on the real phone network.

I'm a Founding Member at Vobiz, telephony for AI voice agents. I write about where voice agents meet the phone network: SIP, phone numbers, latency, echo, barge-in and everything that breaks on real calls but not in browser demos. More at piyushsahoo.me

## Responses

Markdown supported · ⌘↵ to post

No responses yet.