Are you using Aspera with Kaltura?

mkraft Michigan, USAFounder Posts: 78 ✭✭✭

Hi there! If you're using Aspera I'd love to hear more about your use cases and the benefits it provides. We have some remote KMC admins who need a solution for faster large uploads. I'm not really sure Aspera will solve this for them. Thoughts?


Melinda Kraft, Business Systems Analyst Lead (she, her, hers)

University of Michigan - ITS Teaching & Learning

Ann Arbor, MI 48109-3704



  • jmanthony
    jmanthony VA, USAMember Posts: 1

    Good afternoon Melinda!

    A good question, to which I did a test. Note, I did not purchase Aspera for our organization, so I'm not versed on the technial aspects, how it could/should be optimized, etc. I'm just a user. And at home. With a theoretical 10 Mbps upload speed. With a 2 GB (1.95 GB actually) file, the non-Aspera upload straight to the KMC took about 40 min (40:36). And the same file with Aspera took nearly 30 min (29:20).

    So it seems that you are largely bound by the upload speed of your employee's local ISP and whatever service they're paying for. For example, for more a month, I know I can get faster upload speeds. And so my "guess" is that Aspera keeps a file en route in bigger packet sizess. And so with that, combined with whatever algorithm they use to reassemble the file, is where they gain efficiency. Again, a guess on my part re: the technical aspects of how it works.

    Also, FWIW; I had no feedback on the non-Aspera upload other than a progress bar, but the Aspera upload had an activity window where I could monitor the upload speed. And I was getting a bit better than 10 Mbps, until my wife jumped on a video conference on our network. And then speeds dropped to about 9.25 on avg. So another variable.

    But overall, we have Aspera when we need it. And can use it on the much faster network speeds when in the office (where it's blazingly fast), and at home, where again, it seems that you'd remain limited, in large part, to your home upload speeds.


  • thomas_ellis
    thomas_ellis Virginia, U.S.Kalturian Posts: 58 ✭✭

    Thanks for the feedback Joby @jmanthony 🙂

    To add some color to the technical side of things, Aspera uses UDP for data transport vs. a traditional upload which uses TCP. There are two key advantages to UDP here:

    1. UDP is usually used for realtime/live voice/video traffic, so it get's prioritized on most networks, which gives it first access to bandwidth on congested networks.
    2. UDP does not have to have checksums for data packets like TCP does. This stems from it's primary usage in live transport where if a packet was dropped, or corrupted, then it doesn't matter because the server is not going to ask the client to resend it. At that point, the stream has progressed and any prior packets are no longer useful. This just means that UDP does not have to have the constant checksum validation headers in the packets, so there is slightly less data to transfer, and the server side doesn't have to waste time doing error checking. BUT, since Aspera uses this for file transport and not streaming, then they have implemented their own checksums that basically (this is my last understanding, so if it has changed some over the years, then forgive me here) get sent at the beginning of the stream and act like a master manifest for the server to validate against at the end of the stream. If any packets were missed, then it will request the client to resend at that point.

    Side note: because of point 2, then Aspera is actually slower if you were to try to transfer a very large volume (thousands and thousands) of small files (we'll say, smaller than 1MB) as it would have to first build transfer manifests for all of the files before starting transport, at which point traditional TCP would have had enough of a jumpstart to be well into it's transfer progress.

    That's probably more than you care to know about Aspera, but sometimes engineers just need a chance to dump all the random things they know 😋. @mkraft , I'm sure you know me enough by now to have seen that coming 🤪

    Thomas Ellis | Principal Solutions Engineer Kaltura