Introducing (and interest check) AirTalk: Wireless plug-and-play LocalTalk dongles

[jkheiser]

My rainbow set arrived yesterday and I’ve been playing around with them ever since.

As I mentioned in an earlier post, my Orbi mesh network is unfit for the task, so I set up a dedicated wifi network with an ancient Linksys WRT54G running DD-WRT. I joined a pair of AirTalks to this network and then connected them to a pair of Mac Pluses: one running System 7.0.1 as an AppleShare server, and the other running System 6.0.8 as the client. I also spun up an AppleShare client with System 6.0.8 in Mini vMac (v37.03) on a recent MacBook Pro running Monterey. These were the only three Macintosh devices on this network and they were used to copy the same 676,909-byte file using the Finder.

Client	Server	Connection	Time	Rate
System 6.0.8 Mac Plus (real hardware)	System 7.0.1 Mac Plus (real hardware)	Wired	64 seconds	84.6 Kbps
System 6.0.8 Mac Plus (real hardware)	System 7.0.1 Mac Plus (real hardware)	AirTalk-to-AirTalk	112 seconds	48.4 Kbps
System 6.0.8 Mac Plus (Mini vMac v37.03)	System 7.0.1 Mac Plus (real hardware)	Mini-vMac-to-AirTalk	862 seconds	6.2 Kbps

The 43% drop in performance from wired to wireless is a bit more than other AirTalk users have reported. Maybe 802.11g is a factor? 54 Mbps is slow-ish by today’s standards, but I thought it would be sufficient for AirTalk’s needs. Even so, I’m fairly happy with the effective speed I’m getting. Almost 50 Kbps is not bad.

The big surprise was the abysmal throughput with Mini vMac. I tried a different wifi router (Actiontec C3000A) but had the same performance issues. I cut AirTalk out of the equation and used another MacBook Pro to do a Mini-vMac-to-Mini-vMac copy of the same file, but average speeds remained around 5-15 Kbps. Clearly there is something going wrong with Mini vMac on my end.

 

[cheesestraws]

54 Mbps is slow-ish by today’s standards, but I thought it would be sufficient for AirTalk’s needs

It varies more with latency than with bandwidth. LocalTalk is kind of implicitly based around the idea that it has low bandwidth but extremely low latency. It deals ... relatively badly with added latency. WiFi necessarily adds latency, even good WiFi in an uncontended area. If you are having to share spectrum or if your WiFi is just slow at shunting packets through, that'll affect LToUDP much more than it would affect, say, TCP, which has mechanisms to adapt to that kind of thing.

43% drop is nearly the worst end of what I'd expect, but it's not unprecedented. Fiddling with the WiFi network to try to reduce latency is ... possible, but unless you really like fiddling with WiFi kit, may not be worth the candle.

I hope it's not too annoying... :-/

Clearly there is something going wrong with Mini vMac on my end.

Mini vMac's networking code is a little bit odd and performance is very variable. The LocalTalk timers are tied to the screen refresh in a way that it isn't in real hardware, which makes the timings a bit (very) odd. Are you running Mini vMac on a machine that's connected wirelessly? For some reason I've never worked out, over WiFi mini vMac crawls for me, but when I put it on a wired Ethernet connection, it's much much faster. Mini vMac itself obviously doesn't know what connectivity the computer it's running on has, so I wonder whether there's some kind of queueing or power management going on in the WiFi stack?

So if it's not currently on wired ethernet, it might make sense to try it on that. It shouldn't, on the face of it, make any difference, but apparently it does, at least for me...

 

[jkheiser]

You were right about the performance difference using Mini vMac on a wired connection instead of wireless. I just tried it with an AirTalk-connected SE/30 and got speeds of 135 Kbps. Before I was seeing around 5-15 Kbps.

Things just got a lot more exciting! Thanks for the tip, @cheesestraws.

 

[LaPorta]

jkheiser, just need to say I love the Deja vu II card dealer icon!!

 

[jkheiser]

He’s the grim-faced fella the pit boss sends in after Rudy helps you defraud the casino!

 

[drygol]

I am interested in 3 units. Please add me to the list

 

[badCaps]

I did a bit of testing using the following setup:

Server: Beige G3 desktop running 9.2.2
Client: Power Mac 5200/75 running 7.5.3
Transfer: Folder 7.6MB containing 4 files.

Results below. I'm pretty happy with the overall performance. Repeated the tests a few times under different wifi conditions and all performed very similarly. Before I found the IGMPv3 setting, Airtalk was unusable over my Ubiquiti AP. The client would see the server, connect but fail to even start the transfer. I did some other tests with and SE, LC475 and it all worked but didn't capture the results, however the performance seemed comparable. Sometime soon I'd like to test using a pair of Beige G3's to see if having faster machines on each end will improve performance even more.

Connection	Time	Speed (Kbps)
Direct connect serial cable	5m 28s	185.52
Airtalk to Airtalk over old Linksys router WRT120N (802.11a/b/g/n)	10m 55s	92.92
Airtalk to Airtalk over Ubiquiti AP Lite (IGMPv3 enabled)	7m 55s	128.14
Airtalk to Airtalk over Ubiquiti AP Lite (default, no multicast enabled)		unusable

 

[cheesestraws]

Thankyou @badCaps and @jkheiser for the speed information, that's really good to know—and for other people to know . More info about how it works with in various circumstances will help people know if this is really something that'll be useful for them.

Before I found the IGMPv3 setting, Airtalk was unusable over my Ubiquiti AP.

That's interesting—I must have done this on mine and forgotten about it, then! I'm using Ubiquiti stuff here.

 

[Hopfenholz]

Please put me down for 2 of AirTalk adapters. What an amazing innovation, well done!

 

[Katespayed]

Hello!! This is so exciting! Please put me down for 2 air talks!

 

[cheesestraws]

Thanks, all! Since I've had some questions I'll just say:

I'm not acknowledging everyone who expresses interest here individually, but only to avoid cluttering up the thread with lots of me replying without any substance . If you have posted expressing interest in the thread, I will contact you as soon as I can, and I appreciate all the interest and people's kind words.

 

[cheesestraws]

Batch 3 is now ready to go! I've started messaging people again, and I will work through until I either run out of AirTalks or interested people

 

[just.in.time]

You can also network with (at time of writing) the beta of Mini vMac, though I'm sure this code will make it into production sooner or later. (Though this has a few caveats, mostly around speed).

Do you have the manual compile options for Mini vMac that you used to get this working? Was this on version 37.03?

 

[cheesestraws]

Do you have the manual compile options for Mini vMac that you used to get this working? Was this on version 37.03?

Yup, 37.03. You should just be able to provide "-lt" and it should work, though personally I've only tried it on modern Macs. If you are on a modern Mac I can send you a build that I use here and which works.

 

[pax]

Another AirTalk success story.

I'm file sharing my heart out with an SE/30 (7.5.5) and a TAM (7.6.1/9.1). It's working well and I have speeds comparable to earlier reporters. The wireless network an Eero Pro (eeroOS 6.10.3).

Thank you @cheesestraws!

 

[retr01]

Hello @cheesestraws!

I am interested, too! I want two of those AirTalk devices, please. I sent you a PM. Thank you.

 

[just.in.time]

Yup, 37.03. You should just be able to provide "-lt" and it should work, though personally I've only tried it on modern Macs. If you are on a modern Mac I can send you a build that I use here and which works.

Thank you. Do you have the exact line of commands you ran in Terminal? When I run the steps listed on the mini vmac site’s Build page, “make” doesn’t do anything. I don’t think there is a makefile present for it to work with. The steps I ran are as follows:
Download and unzip source code.
cd into minivmac folder
gcc setup/tool.c -o setup_t
./setup_t -t mcar-m SEFDHD -lt > setup.sh
chmod 744 setup.sh
./setup.sh
make

but no makefile for make to work with.
Running on M1 Air on macOS 12.4 with Xcode command line tools installed.

 

[robin-fo]

Thank you. Do you have the exact line of commands you ran in Terminal? When I run the steps listed on the mini vmac site’s Build page, “make” doesn’t do anything. I don’t think there is a makefile present for it to work with. The steps I ran are as follows:
Download and unzip source code.
cd into minivmac folder
gcc setup/tool.c -o setup_t
./setup_t -t mcar-m SEFDHD -lt > setup.sh
chmod 744 setup.sh
./setup.sh
make

but no makefile for make to work with.
Running on M1 Air on macOS 12.4 with Xcode command line tools installed.

-lt is not enough for LToUDP

Use -lt -lto udp -speed z

Do you get any errors when executing setup.sh?

mcar-m SEFDHD

There appears to be a space character missing before the „-m“

 

[just.in.time]

-lt is not enough for LToUDP

Use -lt -lto udp -speed z

Do you get any errors when executing setup.sh?


There appears to be a space character missing before the „-m“

Thank you for the tip regarding the -lt usage. I’ll give that a try.

As for the -m, not sure how I lost the space when copy-pasting what I had ran here, but just double checked and I had a space in the actual command I ran in Terminal.

 

[just.in.time]

Do you get any errors when executing setup.sh?

And no, no errors on setup.sh, only on make.

I’ll post an update after I try the revised -lt options.