Results 1 to 5 of 5
  1. #1
    Join Date
    Jan 2002
    Location
    Charlotte, NC
    Posts
    527

    Ftp: MaxClientsPerIP -- advantage of multiple connections

    Greetings all,

    I would figure this to be a simple question but I'm not finding anything easily on it for some odd reason...

    What's the advantage/disadvantage to using multiple ftp connections to connect from one pc to a hosting account?

    I would assume it would allow multiple actions to happen simulaneously, (i.e. uploading and downloading at the same time) but is there a speed advantage? Specifically in uploading?

    My initial thought is that it wouldn't give you any faster speeds, but I can't seem to find any information to support or negate this.

    Any helpful links or thoughts on the subject?

    TIA,
    Jason
    http://www.charlottezweb.com
    HOSTING your livelihood

  2. #2
    Join Date
    Feb 2005
    Location
    Montreal, PQ
    Posts
    355
    It sure helps greatly... as long as the port can sustain the speeds. For example, download accellerators can improve download speeds from slow servers. Or multiple connections to usenet can improve speed.

    There's a server I have with HostFresh. I can't get more than 15-20KB/s per thread no matter how hard I try... the upload is just too slow. So I'd run 10-20 ftp clients to improve speed... 20*20 = 400KB/s.
    Servers proudly hosted at... WebNX (10) - Netelligent (6)
    Also enjoying services from DreamHost, Hyperspin
    (#) indicates number of servers - 16 total

  3. #3
    Join Date
    Aug 2005
    Location
    Los Angeles, CA
    Posts
    169
    Multiple connections help because the throughput of a single FTP/TCP connection ("thread") is dependent on the round-trip time (RTT or "latency") between the communicating nodes. On a modern TCP implementation, the maximum throughput of a single session with 60 ms RTT (typical between east and west coasts of the US) is about 1 MB/s. Even if you have a dedicated gigabit circuit between the server and client, it won't go faster than that in a single connection.

    If you're interested in the theory behind this, try a search for "tcp throughput". There is a lot of recent and interesting research in this area because the problem is becoming increasingly apparent as throughput increases and latency approaches the speed of light in fiber (which isn't low enough to be negligible). A lot of the work is being done around the Abilene project, where this is already a real problem.
    Expert security, software, and network engineering services (we solve the hard problems)

  4. #4
    Join Date
    May 2005
    Location
    New York
    Posts
    736
    those that are wondering why, in a nutshell its cause traffic isnt one way. a server doesnt send data blinly and assumes it reaches the other end.

    The server sends out a packet of data ( of configurable size ) and then waits for a reply from the other end that it was received before sending the next. Its this step which is dependant on a) ping time and b) responsiveness of the server that limits throughput regardless of bandwidth, as such you can have another stream sending data while stream one is sitting idle basically. And form there keep on adding sessions so that it ends up filling all available bandwidth on yoru connection instead of sitting idle for responses
    Perigee Global Corporation
    Design, Development and Hosting Solutions
    Dedicated Servers, CDN, Hosted E-Mail, Web Hosting, VPS & Cloud Servers
    1.212.400-7632 www.perigeeglobal.com

  5. #5
    Join Date
    Jan 2002
    Location
    Charlotte, NC
    Posts
    527
    Thanks everyone -- this has been very helpful!

    Cheers,
    Jason
    http://www.charlottezweb.com
    HOSTING your livelihood

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •