Why OWA is very slow?

pc_remote--branch ==tunnel== head office--Exch_server
user_a at branch login to OWA and complain it takes long time (30-60") to load the page. It works lot faster in the past.
user_a can load other websites quickly ==> branch Internet connection is OK?
user_a can load OWA pages quickly (1-3") from head office ==> exch_server is OK?
There is no traffic shaping for the tunnel. No change to the tunnel setting.
user_a mailbox size is normal - 80MB.
Q#1. Any idea why user_a has such different speed?
Q#2. How can I 'dig' deeper to find out what 'slows' it down?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Scott, MCSENetwork AdministratorCommented:
does this user have a large number of items in their mailbox?

are you using FBA (forms based authentication)

there is an option to select the basic client for lower bandwidth situations.  

are you requiring https for OWA? or is the user connecting via a vpn?

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
richtreeAuthor Commented:
user_a has only 151 items in Inbox.
user is required to provide domain name, user name, and password. This is always the same in the past.
Why FBA takes more bandwidth?
user_a is using http for OWA, connecting not via vpn.
again there is no network change.
David Scott, MCSENetwork AdministratorCommented:
http or https?  what is this user tries OWA from another computer that is not at your headquarters?  

Simplify Active Directory Administration

Administration of Active Directory does not have to be hard.  Too often what should be a simple task is made more difficult than it needs to be.The solution?  Hyena from SystemTools Software.  With ease-of-use as well as powerful importing and bulk updating capabilities.

richtreeAuthor Commented:
user_a can load OWA normally from another pc at branch.
I restart user_a's pc at branch and it can load OWA page normally too.
Q#3. Why user_a's pc has a problem with OWA but not other websites? I understand the pc may accumulate some 'garbage' which should affect all IE browsers, not just a specific one. Is it because OWA needs a lot more resources than a regular web page?
David Scott, MCSENetwork AdministratorCommented:
nah owa page isn't resource intensive, the temp file for the page may have become corrupt or the dns cache entry for the page went bad.  
richtreeAuthor Commented:
how to check the temp file for this page or the dns cache entry for the page?
David Scott, MCSENetwork AdministratorCommented:
cmd prompt

ipconfig /displaydns

internet explorer, tools, internet options, general tab, settings, view files
richtreeAuthor Commented:
I guess if dns file is incorrect, then it cannot load the OWA page at all. But it does load it correctly though extremely slow. Do you still think that it might be related to the dns file?
How can I verify if the temp files are corrupt?
David Scott, MCSENetwork AdministratorCommented:
i don't know of a way. but if clearing the temp files resolved, you can assume that is the case.  

right on the dns actually.  if the entry was cached was wrong or bad that it wouldn't be able to resolve the url

you could try replacing the servername with ip in the url for testing if it happens again. that would tell you its dns
richtreeAuthor Commented:
Thank you for your ideas.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Web Browsers

From novice to tech pro — start learning today.