HPQC ALM 11 REST API Total Entity Return LIMIT

I am moving my project using from OTA to REST API.

OTA often crash. If many use use the same time, OTA single connection cannot handle it. If anyone out there have solution, please share with me. 

When using REST API, 

http://www.server.com/qcbin/rest/domains/DOMAINNAME/projects/PROJECTNAME/tests?query={parent-id[1234]}&fields=id&login-form-required=y 

Entities TotalResults is let's say 150.

But Actually Entity return in XML node is only 100. Is that REST API LIMITATION ???