RTPTRANS(1)

📦 version 1.22, in nixos 26.05, nixpkgs unstable

💅 RTPTRANS(1) — the rtptrans girlies' edition 🎀

okay so this is the manual page for rtptrans, a General Commands Manual situation, and honestly? she's niche but she serves. here's everything, no gatekeeping. 🫶

✨ NAME ✨

rtptrans — translate RTP between unicast and multicast networks

like, she's a translator. for networks. multilingual icon behavior fr fr 🌈

✨ SYNOPSIS ✨

rtptrans [-h] address/port[/ttl] address/port[/ttl] [...]

bestie the whole invocation is just a lil list of address/port[/ttl] situations and you can keep stacking them, and there's a -h in there too — the page does not elaborate on -h and I'm not gonna make stuff up, so that's all we're saying about it 💀

✨ DESCRIPTION ✨

okay so the entire personality of rtptrans is this: it takes RTP/RTCP packets that arrive from one of the addresses you specified, and translates them out to all the other addresses you specified. that's it, that's the job. she's a little switchboard with a heart of gold 💖

the addresses can be multicast or unicast — both are welcome here, no dress code 🌸

and those optional TTL values? ignored for unicast addresses. like, she sees them, she just doesn't care. it's giving "read at 4:47 PM." 🦋

🧚 bonus behavior: the VAT situation (iykyk)

additionally — and this is the part that makes her interesting — the translator can translate VAT packets into RTP packets. not me being multifunctional 💅

so here's the lore: VAT control packets get translated into RTCP SDES packets with a CNAME entry and a NAME entry. cute, right? BUT — and this is a big but —

⚠️ this is only intended to be used in one very specific configuration, so don't get creative. this is not a "do whatever" feature, this is a "do exactly this" feature.

the configuration in question: VAT packets arriving on a multicast connection are translated into RTP and sent over a unicast link. that's the whole allowed vibe.

and just so we're clear, because someone will ask:

  • RTP packets are not yet translated into VAT packets. not yet. she's working on it. 🙈
  • packets arriving on unicast links are not changed at all. zero edits. hands off. ✋

because of all that, only one topology is supported, and it's directional, so pay attention bestie:

  • on the way in: “multicast VAT -> translator -> unicast RTP”
  • on the way back: “multicast VAT <- translator <- unicast VAT”

which means the audio agent on the unicast link should be able to use both VAT and RTP. she's bilingual, she just needs you to respect the arrangement 💜

✨ AUTHORS ✨

credits time, we love to see it 👑

  • rtptrans was written by Henning Schulzrinne <hgs@cs.columbia.edu>
  • with enhancements by Dorgham Sisalem <sisalem@iptel.org> and Steve Casner

three icons, one command. no cap. 🔥

🎀 asides corner: this page is the Debian flavor of the manual, and it was dated November 23, 2017 — so yes, she's an elder Gen Z but she still ate and left no crumbs. periodt. ⭐

okay ily, go translate some packets, mwah 💋✨

📦 where this page comes from