Mbps VS. Ping, which one is more important? advice needed!!!

Discussion in 'Hardware' started by SuperLimitUser, Aug 18, 2007.

which one should i use?

  1. CABLE

    12 vote(s)
  2. ADSL

    10 vote(s)
  1. I have 2 ISPs, trying to decide which one to be the primary line.

    -CABLE, up to 25mbps download(usually 10mbps when i did speedtest from speakeasy.com), 85 ping to the trading server i use. the ping test was min 80ms, maximum 102ms, average 85ms.

    -ADSL, up to 6mbps download(usually 3mbps download from the test), 61 ping to the trading server. the ping test was really consistant, min 60ms, maxium 62ms, average 61ms.

    Both of them have 900 kbps upload speed. and both of them are public lines.

    Please advise me which one to be the primary line for trading.

    Thank you for your input!
  2. do you trade manually? (i'm betting this is you), the difference is smaller than the time you even can react to a print on the tape. it does not make any difference. I'll take the one with the higher throughput (bandwidth)
  3. dcvtss


    maybe do a trace too and see which one has the fewest hops
  4. ken__0


    dsl is more reliable imo
  5. If you trade manually then the speeds and response times are effectively the same.

    Choose the one that has fewer outages.

    If you have a machine then choose the one with the lower response time (ping) while you are collecting trading data. As long as your data feed doesn't exceed the total bandwidth.
  6. TGregg


    If you are a serious trader, you'll get both.

    If you are pulling in say $400 a day, by not losing one day of trading every 10 months will pay for the extra service. Not to mention avoiding that wonderful feeling of special joy when you just initate a large position and your ISP tanks. Sure, you can call your broker. Chances are, you'll get some pretty decent hold music. But that's not exactly direct access, is it?

    They make special routers that will run to both DSL and Cable modems, switching to the backup when the primary dies. Get one of them and get both DSL and Cable.
  7. JackR


    Most ping tests use very small ping packets. They simply show round-trip time to and from the pinged location. The test does not show packet loss. If, during a market day, your link experiences packet loss, your effective link speed decreases. This is a result of the TCP/IP protocols the Internet uses to provide us with connectivity.

    A typical ping packet may be 32 bytes. Depending on what you are sending/receiving from your trading/charting platform, your packet size will easily be 10 to 20 times larger. If there is a problem (noise, congestion, route switching, etc.) and the packet is detected as bad, the TCP protocol will detect the problem and request a resend of the bad packet. This holds up any good packets until they can be properly recombined. Thus, "packet loss" adds delay to your transmission time. It is far more noticeable using "real" packets than it is using ping-sized packets.

    You don't exactly say so, but you appear to have both cable and DSL running now. If this is true, then before making your choice download the free version of PingPlotter (www.pingplotter.com). Run it during trading hours on both the cable path and the DSL path. Look at the path graph and note whether there are any numbers appearing to the left of the individual path segment ip addresses (column is labeled PL%). Those numbers are retransmissions (lost packet) requests. Also look at the graph. The individual plot points should have no (or short) horizontal lines associated with them. This is the path variation for that leg. No line is good. Long lines, bad. In interpreting the line length remember that auto-scaling is used. If you really want to invest, pay the $30 for the paid version of PingPlotter. It adds another graph at the bottom that shows packet loss over time.

    Lots of transmission speed doesn't really help if there are a lot of retransmission requests going on in the background. Depending on the number of quotes you receive (and your vendor), the greater speed can help keep you up to speed with the market during very busy periods.
    If your computer is able to receive and process (or locally buffer) the info from the vendor's server very rapidly, the vendor's buffers don't fill up waiting for you. If it can't, your machine must play catchup. This is not true for InterActive Brokers. Their quotes are essentially time-sliced (sort of sampled so some quotes/trades may be missing, but the amount of data transmitted remains constant and current during busy periods). Thus for IB, gobs of bandwidth (transmission speed) is not necessary. But - packet loss is a problem for either approach.

    Have fun,

  8. Can anyone recommend hardware which runs both Cable/DSL at the same time.

    I had some serious problems this week and its time I get both Cable & DSL.
  9. If all you're doing is trading, then the ping test (latency) is more important than the bandwidth. It's the amount of time your order will go from your pc to the brokers. Obviously, if your bandwidth is low and you're downloading large files, your latency will shoot through the roof so I'm assuming you're not downloading much.

    In fact, even if you're in japan with a 100 mbps link and a 150 ms latency, you'd be better off in the US with a 384 kbps and a 30 ms latency.

    FYI: I was a Network Engineer / VoIP engineer before I took a year off to trade full time so I do know what I'm talking about (well most of the time) :)
  10. thanks for the reply guys.

    i have both of them up, and i use a dual wan router to connect them all in case one fails. my question is which one should i use as primary line.

    so its pretty much 10Mbps/80ms combo vs. 3.5Mbps/60ms combo. its interesting that the DSL ping is more stable.

    yes i trade manually, and i scalp quite intensivly. getting in and out within seconds all day long.
    #10     Aug 18, 2007