VDAAERL(1)

💖 VDAAERL — bestie's guide to measuring echo-return loss 💖

okay so this is vdaaerl, part of the Voicetronix Telephony Tools, and it lives in section 1 of the manual. if you've ever been like "hmm is this phone line acting weird and echoey", this little icon is literally the answer to your prayers 🫶

✨ SYNOPSIS ✨

vdaaerl [options]

that's it. that's the whole vibe. no positional args, just vibes and flags 💅

🌸 DESCRIPTION 🌸

so the vdaaerl utility does one thing and does it beautifully: it tests the echo-return from a telephone line that's hooked up to a Voicetronix FXO module — think the kind of modules used on the OpenPCI range of cards. and bestie, it can scan all available impedance values to hunt down the best match for a particular line. it's giving detective energy 🔍

it's gonna wait for an incoming call on the port under test. so when that call comes in, whoever's calling needs their handset's microphone well muted for the entire duration of the test. like, muted muted. not "I think it's muted". fr fr.

then a series of tones gets played down the line to figure out the ERL across several parts of the audio spectrum 🎶 and this is important: you should avoid creating any other noise on the line while the test is running, or the results may be skewed. so no side quests, no background chatter, no nothing. main character is the test 🎀

and if you don't specify an --impedance, and you're not using the --scan option, then the default impedance value gets used — which is based on the port's country selection. iykyk 🌍

👑 OPTIONS 👑

here's the full roster, no skips, no cuts:

• --help, -? — shows you a lil summary of the options. when in doubt, ask for help, that's self care 💜
• --card number — explicitly pick which card to test. the default is card 0. 💳
• --port number — explicitly pick which port to test. the default is port 0 of the card being tested. 🚪
• --impedance number — test one particular impedance setting, in the range [0 - 15]. 🎚️
• --scan — test all available impedances. go big or go home. ✨
• --playgain db — set the hardware play gain. values may range from -12.0 to 12.0. 🔊
• --recgain db — set the hardware record gain. values may range from -12.0 to 12.0. 🎙️

heads up bestie: those gain ranges are -12.0 to 12.0, both of them, exact same numbers. don't get creative with the decimals, okay? 🫶

🦋 SEE ALSO 🦋

• proslicerl(1)

go read that one too, it's the sibling energy this page needs 🌈

🎀 AUTHOR 🎀

Ron Lee, Peter Wintulich, David Rowe, Voicetronix <support@voicetronix.com.au> 👑

and this manual page was written by Ron <ron@debian.org>, for the Debian project — but it may be used by others, because sharing is caring 🫶

and that's the whole thing!! this page came to you from the VPB driver package, dated Oct 11, 2007. yes, it's a vintage baddie, and yes, it still ate 💅✨