rest - RESTful WCF call is blocked until previous call is complete -

i've got simple wcf restful service being hosted in iis. call wcf using browser. call service simultaneously using different tabs in browser. below code service

[servicecontract] public interface iwcfservice {     [operationcontract]     [webget(uritemplate = "dowork", responseformat = webmessageformat.json)]     string dowork(); }  public class wcfservice : iwcfservice {     public string dowork()     {         string ret = "enter time " + system.datetime.now + " " + system.datetime.now.millisecond;         system.threading.thread.sleep(10000);         ret += ". exiting time " + system.datetime.now + " " + system.datetime.now.millisecond;         return ret;     } } 

and below web.config file

<?xml version="1.0" encoding="utf-8" ?> <configuration>   <system.servicemodel>     <behaviors>       <servicebehaviors>         <behavior name="wcfservice.wcfservicebehavior">           <servicemetadata httpgetenabled="true" />           <servicedebug includeexceptiondetailinfaults="false" />         </behavior>       </servicebehaviors>       <endpointbehaviors>         <behavior name="wcfservice.wcfservicebehavior">           <webhttp/>         </behavior>       </endpointbehaviors>     </behaviors>     <services>       <service behaviorconfiguration="wcfservice.wcfservicebehavior" name="wcfservice.wcfservice">         <endpoint address="" binding="webhttpbinding" contract="wcfservice.iwcfservice" behaviorconfiguration="wcfservice.wcfservicebehavior">         </endpoint>         <endpoint address="mex" binding="mexhttpbinding" contract="imetadataexchange" />       </service>     </services>   </system.servicemodel> </configuration> 

even though enter address in quick successions end time of first beginning time of second eg output of 1 page is

• enter time 12/05/2015 4:55:24 pm 568.
• exiting time 12/05/2015 4:55:34 pm 569.

then next page

• enter time 12/05/2015 4:55:34 pm 578.
• exiting time 12/05/2015 4:55:44 pm 579.

what causing , how can fix calls processed arrive?

i'm not sure can try set concurrencymode on multiple servicebehavior attribute on implementing class

[servicebehavior(concurrencymode = concurrencymode.multiple)] public class wcfservice : iwcfservice