Long delay in responding to web page request

[Shashi Alabur]

I have 3 different embedded products, all of them display a web page when you type in their ip address in the browser on a computer or laptop.
I have 3 different routers, a DLINK DIR-300, DLINK DIR-600, TPLINK-TLR470+.
Only one Router is used at a time and all devices in my office are connected to this router which is also the DHCP server for all devices on the network.

Two of my products display their web page without any problem on my laptop when any of these 3 routers are used as the DHCP Server in my office network.
The third product works properly when the DIR-300 Router is used, where the web page comes up immediately, but not so with the other two routers.
The web page takes nearly 4 to 5 minutes to display when I use the DIR-600 or TLR470+ as my office router (only for this third product).

A Wireshark tcp/ip capture session also does not seem to show up any problems, though I am not an expert at this and I could have missed something.

What could possibly cause this problem ?
Any pointers, questions, additional information that would help to understand this problem ?
Appreciate the help !

 

[DrB0b]

What are the ping times to each of these devices with each of the different routers? Run a continuous ping to each, let it go at least 20 times, and post below. Are each of these devices connected via wifi or physically connected?

Learning - A never ending quest for knowledge usually attained by being thrown in a situation and told to fix it NOW.

 

[Shashi Alabur]

Hi Bob, Thanks for getting back to me !

Well, in all my testing, my Laptop is on a wired connection to the Router and so is my device.
The device is a Data Buffer, which collects input data from Serial or Parallel or Ethernet inputs and this data may be viewed as a web page in a browser.
Once this web page is displayed, the user may click on the "Settings" option to view/modify the input settings & network settings.

With all 3 routers, the ping timings are less than 1 msec.
While testing with the DIR600 & DIR300 Routers, only my Laptop and the Buffer device were connected to the Router.
Internet being there or not did not make any difference to my observations.

I have a "Locator" program, which basically does a UDP broadcast on port 2002 and any Buffer device present in the network responds on port 2003
My readings are as below (given for TPLINK - DIR 300 - DIR 600 routers, in that order)

Ping : 1 msec, 1 msec,1 msec
To appear in the "Locator" program window : 30 seconds, 2 seconds, 60-80 seconds
Web page open : 60 to 90 seconds, 3 to 4 seconds, 3 to 4 minutes
Settings page open : 80 to 90 seconds, 2 to 3 seconds, 2 to 3 minutes

The "Locator" program taking a long time to receive a UDP response could have been attributed to ports 2002/2003 being blocked in the newer Routers (TPLINK & DIR600).
But, the delayed response for the web page display is something we are unable to understand or explain !

I have 10 of these devices and all of them show the same behavior.

What other information can I give you ? Any other tests that you feel would help in understanding this problem ?

 

[Shashi Alabur]

A continuous ping for more than 100 pings were all less than 1 msec on my TPLINK router

 

[DrB0b]

So when you are trying to get to the web page of each device to do viewing or configuration, what is the exact URL you are typing? Are you just typing the IP address of the device, such as 192.168.0.200. Or are you typing in the IP and a Port, such as 192.168.0.200:2003? You may have to do some port forwarding to make this work correctly.

At least your pings are constant throughout the router rotation. That at least means you have constant connectivity to your device.

Learning - A never ending quest for knowledge usually attained by being thrown in a situation and told to fix it NOW.

 

[Shashi Alabur]

Hi .... I had submitted a reply to your last post, but somehow it is not showing up !!

Anyway.... we always use only the IP address in the browser, as it is on Port 80.

We are not worried about the UDP broadcasts on ports 2002/2003 as this is used by the Locator program and is usually required only at installation. But, the long delay in the browser page display is worrisome.

We have been selling these devices in USA during the past couple of years and no one has complained of this problem !

Still a little lost in understanding the problem ! Wondering where to go from here.....

 

[DrB0b]

I would start by disabling all security, related to HTTP or HTTPS traffic, on the router that takes forever to reach the endpoint and see if that makes significant difference. It has to be some software issue that is slowing the traffic down.

Learning - A never ending quest for knowledge usually attained by being thrown in a situation and told to fix it NOW.

 

[allworxguy]

It might be as "simple" as router/browser compatibility. Have the routers been loaded with their respective latest firmware? Have you tried different browsers?

Marv ccna