4 ms·

I routinely ssh into my experiment at the south pole during satellite windows. I just use tmux on the other end...

by cozzyd 3y ago

cdelsolar 3y ago
How is the latency as you type?
- cozzyd 3y ago
  Same as any non-LEO satellite link (probably like, O(700 ms) latency? About the same as our experiments in Greenland...). Not great, but fine for administration and light vimming. The worst was when I had to update some py2 to py3 code after a system was updated, and there was no way to test except on the South Pole machine. The places where bytes vs. strings bite you when dealing with serial devices are plentiful...
  - anthk 3y ago
    With mosh you can even resume connections after disconnecting but without losing interaction with the target machine as it happens under SSH. Also, it will use far less bandwidth. I tried it with 2G/ISDN-DSL like speeds and it worked great. And you can keep using tmux just in case. On the "caveats", you need UTF8 support in the client machine, but today that's granted.
    - cozzyd 3y ago
      I'm sure there are some advantages, but I couldn't quickly figure out how to get it running with the various jump hosts required (and I also often use port forwarding...). Just having tmux on the other side gets me most of the advantages, I think...
      - anthk 3y ago
        Well, on port fwd, maybe if you forward the mosh server port would work. If you use SSH itself as a tunnel, the setup it's far complex, as mosh is just a remote shell. Still, mosh curb-stomps ssh on latency, input guesssing, data saving and bandwith usage. Using that over 2G was a literal black/white difference compared to SSH which was nearly impossible to connect and the latency was unbearable. Under mosh I could chat, email, nntp (they still are some good newsgroups), IM over jabber/telegram, read news over RSS, code in C/TCL (jimsh) and read the docs with links, among reading books (novels and essays) with some CLI epub reading script. Yes, I also used tmux on the remote machine too, mosh+tmux work great with each other. Albeit mosh resumes a potentially lost/dropped connection just fine (even without a running remote tmux/screen), I think tmux itself would send less data over the wire.
  - cdelsolar 3y ago
    This stuff is always so fascinating to me. I remember I was on a plane once and I had done a code deploy before getting on the flight, then remembered I forgot to upload the necessary files to the k8s cluster. There's no way I had enough bandwidth on a plane to get the files on the cluster. So I tried ssh-ing to my home machine and doing it from there -- nope, SSH is blocked on the stupid in-flight Wifi. So I went on DigitalOcean, got a $4 instance, and used the web interface to SSH into my home machine, and then from the home machine uploaded the files to the cluster. The latency was hilariously slow, I think over 1 second, but it worked! I was thinking about the route those packets were taking - from my computer to the plane router, up to a satellite, down to the DO data center in NY, from there to my home in NJ, then to the K8s cluster in NY, and then all the way back around. When you put it that way, one second per character isn't that bad.
richwater 3y ago
Can you talk about this a little more?
- makeworld 3y ago
  Their website (in bio) looks relevant.
- cozzyd 3y ago
  Sure... I work on experiments where we basically we instrument ice sheets with radio antennas and look for radio emission that might come from really energetic particles smashing into the ice. One of the experiments I work on (the Askaryan Radio Array) is at the South Pole. Each detector has a single board computer to take data and such. They are cabled via fiber to the IceCube lab at Pole, where data is relayed to. About half the time, the South Pole has internet either via NASA satellites or DSCS (there is also Iridium all the time, but that is not for general use), and via some jump hosts, I can ssh into the detectors.
  - richwater 3y ago
    Very cool, Thanks!
SenHeng 3y ago
Is starlink available?
- cozzyd 3y ago
  It's a delicate question. Starlink does have some satellites in polar orbit (initially it seemed like there wouldn't be any, so this is relatively new), and there were some limited Starlink tests last year, but due to the CMB telescopes at Pole, which may be negatively impacted both by the satellites and the ground antennas, any Starlink deployment will be very cautious.
  - inemesitaffia 3y ago
    Tested and rejected due to interference
    - cozzyd 3y ago
      Studying coexistence is an active area of effort (we even applied for some NSF funding to study this...)

I routinely ssh into my experiment at the south pole during satellite windows. I just use tmux on the other end...

by cozzyd 3y ago

I routinely ssh into my experiment at the south pole during satellite windows. I just use tmux on the other end...

cdelsolar 3y ago

How is the latency as you type?

cozzyd 3y ago
Same as any non-LEO satellite link (probably like, O(700 ms) latency? About the same as our experiments in Greenland...). Not great, but fine for administration and light vimming. The worst was when I had to update some py2 to py3 code after a system was updated, and there was no way to test except on the South Pole machine. The places where bytes vs. strings bite you when dealing with serial devices are plentiful...
- anthk 3y ago
  With mosh you can even resume connections after disconnecting but without losing interaction with the target machine as it happens under SSH. Also, it will use far less bandwidth. I tried it with 2G/ISDN-DSL like speeds and it worked great. And you can keep using tmux just in case. On the "caveats", you need UTF8 support in the client machine, but today that's granted.
  - cozzyd 3y ago
    I'm sure there are some advantages, but I couldn't quickly figure out how to get it running with the various jump hosts required (and I also often use port forwarding...). Just having tmux on the other side gets me most of the advantages, I think...
    - anthk 3y ago
      Well, on port fwd, maybe if you forward the mosh server port would work. If you use SSH itself as a tunnel, the setup it's far complex, as mosh is just a remote shell. Still, mosh curb-stomps ssh on latency, input guesssing, data saving and bandwith usage. Using that over 2G was a literal black/white difference compared to SSH which was nearly impossible to connect and the latency was unbearable. Under mosh I could chat, email, nntp (they still are some good newsgroups), IM over jabber/telegram, read news over RSS, code in C/TCL (jimsh) and read the docs with links, among reading books (novels and essays) with some CLI epub reading script. Yes, I also used tmux on the remote machine too, mosh+tmux work great with each other. Albeit mosh resumes a potentially lost/dropped connection just fine (even without a running remote tmux/screen), I think tmux itself would send less data over the wire.
- cdelsolar 3y ago
  This stuff is always so fascinating to me. I remember I was on a plane once and I had done a code deploy before getting on the flight, then remembered I forgot to upload the necessary files to the k8s cluster. There's no way I had enough bandwidth on a plane to get the files on the cluster. So I tried ssh-ing to my home machine and doing it from there -- nope, SSH is blocked on the stupid in-flight Wifi. So I went on DigitalOcean, got a $4 instance, and used the web interface to SSH into my home machine, and then from the home machine uploaded the files to the cluster. The latency was hilariously slow, I think over 1 second, but it worked! I was thinking about the route those packets were taking - from my computer to the plane router, up to a satellite, down to the DO data center in NY, from there to my home in NJ, then to the K8s cluster in NY, and then all the way back around. When you put it that way, one second per character isn't that bad.

richwater 3y ago

Can you talk about this a little more?

makeworld 3y ago
Their website (in bio) looks relevant.
cozzyd 3y ago
Sure... I work on experiments where we basically we instrument ice sheets with radio antennas and look for radio emission that might come from really energetic particles smashing into the ice. One of the experiments I work on (the Askaryan Radio Array) is at the South Pole. Each detector has a single board computer to take data and such. They are cabled via fiber to the IceCube lab at Pole, where data is relayed to. About half the time, the South Pole has internet either via NASA satellites or DSCS (there is also Iridium all the time, but that is not for general use), and via some jump hosts, I can ssh into the detectors.
- richwater 3y ago
  Very cool, Thanks!

SenHeng 3y ago

Is starlink available?

cozzyd 3y ago
It's a delicate question. Starlink does have some satellites in polar orbit (initially it seemed like there wouldn't be any, so this is relatively new), and there were some limited Starlink tests last year, but due to the CMB telescopes at Pole, which may be negatively impacted both by the satellites and the ground antennas, any Starlink deployment will be very cautious.
- inemesitaffia 3y ago
  Tested and rejected due to interference
  - cozzyd 3y ago
    Studying coexistence is an active area of effort (we even applied for some NSF funding to study this...)