A real screenshot I took from a piece of industry-standard SIP telephony middleware

No, you cannot type in them it's grayed-out. The developer wanted to make sure you only used numbers so they put in a slider.

Here's a video of the numerical input sliders in Brooktrout SIP middleware. Yes, this is real, I recorded it in 2017. No, you cannot type into the boxes.
@SwiftOnSecurity Can you "nudge" a value by exactly 1? Like if you need 109 but you're at 108.
@aismallard @SwiftOnSecurity Yep, with left/right arrow keys, at least?
@mdm @SwiftOnSecurity I would hope but with this I'd be worried that the answer is no lol
@aismallard @SwiftOnSecurity praying that the arrow keys work
@SwiftOnSecurity dropdowns for booleans instead of checkboxes is also nice.
What a cursed UI this is. šŸ˜‚
@SwiftOnSecurity omg could you at least use the < and > arrow keys to move the slider with more precision?
@chucklebags @SwiftOnSecurity oh good point! unless they explicitly disabled it, that *should* be the default behavior for that control.
@SwiftOnSecurity oh god, brooktrout, I’m having Edify flashbacks
@SwiftOnSecurity I can feel that stupid interface...
@SwiftOnSecurity I especially love that you can send 5xx (server failure) and 6xx (global failure) but not 3xx (redirection) for call not answered
@SwiftOnSecurity
I am surprised that the sliders did not also bring up an audio track of demonic laughter. MUAHAHAHAHAHAHAHAHAHAHA!
@SwiftOnSecurity Gosh. I thought I had seen the worst with Avaya CMS Supervisor in my callcenter days, but I guess this will replace that nightmare in my dreams now.
@SwiftOnSecurity IIRC, Brooktrout cards were VERY expensive too. I think we had a few T1 cards in some Deliveryware servers.
@SwiftOnSecurity obviously sliders are only to be operated with the arrow keys!!