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  1.    #1  
    Frustrated by why images weren't loading in Blazer on my new Treo 300, I digged into how exactly Blazer downloads web pages.

    I installed a web proxy on a server I control, and pointed Blazer at my proxy. My proxy dumps information about all web requests passing through it.

    I then powered up Blazer and tried to fetch "http://treocentral.com". My proxy reports that the Treo sent a web request for this URL:

    Code:
    http://proxy.handspring.com:80/a=QPOSYwJq&c=F61B888774506829CF65A07C6D21A917/http/80/treocentral.com/
    proxy.handspring.com replied with some content, with content-type text/vnd.wap.wmlc. The Blazer proxy is actually sending WAP pages to Blazer, not raw HTML. Images are also reformatted; they have MIME type image/vnd.palm.pbmp.

    Then I tried telnetting to proxy.handspring.com and requesting that URL myself. I found that you must set the User-Agent to "Blazer/2.1.1", otherwise proxy.handspring.com immediately drops the connection. When you do set the user-agent, and request that URL, proxy.handspring.com returns the first 1448 bytes ---about one MTU --- and then drops the connection. That number (1448) keeps recurring; when I check the page properties in Blazer, it claimed that several different pages, including cnn.com, were 1448 bytes long. That's not likely a coincidence.

    Suppose proxy.handspring.com is misconfigured so that all URLs it serves are truncated after the first couple hundred bytes. Since the proxy is reformatting pages from HTML into the more compact WML, most web pages will have most of their useful content in the first 1k of bytes --- thus most pages will display, to some degree. However, images will tend to be bigger than a couple hundred bytes, and Blazer may not be able to render truncated image files.

    Both of those are consistent with the behavior I'm seeing, which is that most web pages will load somewhat --- although the bottom of the page may be missing on longer pages --- and almost all images are simply blank.

    My only question is, how do I get an engineer inside Handspring to listen to me and get this fixed? Handspring handed off all customer support to Sprint, but this is clearly a problem with Handspring's server.
  2. #2  
    Hmm. My Blazer images have been working fine.

    Blazer uses HTTP/1.1 and does everything through the one connection. As you note it is essentially a WAP browser, and the proxy converts everything to WAP counterparts. Since it still makes individual requests for each image, it's pretty chatty on the send side, which is bad news for those of us in poor coverage as it really sucks down the juice.

    I'm not sure why your's isn't working. Perhaps lack of available RAM? Also, what's your cache size?

    I once snooped on the Blazer traffic by running the emulator and using tcpflow.
  3.    #3  
    My Treo is only half full (~7Mb free). I've tried cache sizes of 1000 and 2000, no difference. I also tried clearing the cache, and a soft reset.

    Perhaps your images are cached? I was seeing images on Thursday, so it must have broken between now and then.
  4. #4  
    Originally posted by tlau
    Perhaps your images are cached? I was seeing images on Thursday, so it must have broken between now and then.
    Doesn't appear so. I see around 82K get loaded from www.treocentral.com just a second ago. Images came up ok. Reload is around 20K. Then if I go in and clear cache and reload, it is 82K again.

    I'm not using the proxy option in the preferences. You still using a proxy? Are you sure it supports HTTP/1.1?
  5.    #5  
    I get the same results whether or not I have a proxy configured in Blazer. In fact I only started using the proxy to try and diagnose the "blank images" problem.
  6.    #6  
    It could be a Blazer version difference... I have version 2.1.1s2 Build 31.

    On my old Treo 180 (GPRS), which has Blazer 2.1.3 Build 12, images load fine. When I connect that Blazer to my proxy, it tries to contact a different host (hproxy.handspring.com:443), and that handspring proxy doesn't truncate its responses.
  7. #7  
    Originally posted by tlau
    It could be a Blazer version difference... I have version 2.1.1s2 Build 31.

    On my old Treo 180 (GPRS), which has Blazer 2.1.3 Build 12, images load fine. When I connect that Blazer to my proxy, it tries to contact a different host (hproxy.handspring.com:443), and that handspring proxy doesn't truncate its responses.
    Mine is 2.1.1s2 Build 31 also. Let me do some simple tests.

    I requested a web page off of my server. In the logs it is:

    blazer-fetch.handspring.com - - [07/Jun/2003:23:58:57 -0400] "GET / HTTP/1.1" 200 4094
    64.75.2.10 - - [07/Jun/2003:23:59:01 -0400] "GET /icons/jhe061.gif HTTP/1.1" 200 17175
    64.75.2.10 - - [07/Jun/2003:23:59:02 -0400] "GET /icons/debian/openlogo-25.jpg HTTP/1.1" 200 1258
    64.75.2.10 - - [07/Jun/2003:23:59:05 -0400] "GET /icons/apache_pb.gif HTTP/1.1" 200 2326
  8.    #8  
    I tried the same thing with Blazer and my web page (http://ofb.net/~tlau/).

    My server logs show:

    64.75.2.10 - - [08/Jun/2003:15:50:35 -0700] "GET /~tlau/ HTTP/1.1" 200 939 "-" "
    UPG1 UP/4.0 (compatible; Blazer 1.0)" 0 ofb.net
    64.75.2.10 - - [08/Jun/2003:15:50:37 -0700] "GET /~tlau/pics/moon-small.gif HTTP
    /1.1" 200 4871 "-" "UPG1 UP/4.0 (compatible; Blazer 1.0)" 0 ofb.net
    64.75.2.10 - - [08/Jun/2003:15:50:39 -0700] "GET /~tlau/pics/moon-small.gif HTTP
    /1.1" 200 4871 "-" "UPG1 UP/4.0 (compatible; Blazer 1.0)" 0 ofb.net

    ... and 42 more requests for the same image, moon-small.gif. On the Treo, I see Blazer receiving somewhere around 84kb, but no images ever appear.

    What happens when you hit my web site?
    Last edited by tlau; 06/08/2003 at 06:08 PM.
  9. #9  
    Originally posted by tlau
    I tried the same thing with Blazer and my web page (http://ofb.net/~tlau/).
    (snip)
    What happens when you hit my web site?
    From my Treo 300 w/ Blazer I get a picture of a moon that's approx 2/3 of the screen size. Other pictures are working too, portrait and cats etc. My settings are High Color images and 256k of cache.
  10.    #10  
    I don't know what's going on there. With the exact same settings (high color images, 256k cache, I cleared the cache and did a soft reset to make sure nothing was left), I fetched the same web page and my server says that Handspring's proxy keeps requesting the same moon image over and over again. My Treo never displays the image.

    I wonder what's different.
  11. #11  
    Originally posted by tlau
    I don't know what's going on there. With the exact same settings (high color images, 256k cache, I cleared the cache and did a soft reset to make sure nothing was left), I fetched the same web page and my server says that Handspring's proxy keeps requesting the same moon image over and over again. My Treo never displays the image.

    I wonder what's different.
    I notice our requests are somewhat different. I should tell you that my test server was on :81 and possibly that makes it not go through some Sprint stuff.
  12.    #12  
    I did a hard reset and now Blazer is loading images again. Go figure. I'll restore my backup bit by bit to try and figure out which particular app causes Blazer to break.

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