push notification is not staying for too long (showing on the display for only 10sec)

Hello,

I saw all of the community messages regarding push notifications and tried all of them. Non of the example worked for me (i don't know how it works for others). Here is my working example

curl --digest -u Push:Push -d "<PolycomIPPhone><Data priority=\"critical\">welcome To Polycom</Data></PolycomIPPhone>" -H "Content application/x-com-polycom-spipx" -k https://PHONE IP/push

My question is: push message is displaying for 10sec only on the phone display, is there any way that i can increase the time?  Is there any way that push message will dispaly on the phone until someone press some button (HOME/EXIT/or any other key) on the phone?

And also how can I give control to the user on Polycom upgrades (if i push the new firmware to the phones it will say like new firmeare is avilable if you want to upgrade press reboot or anything else)? is there any way that i can do that? I am using global provisioning server (000000000000.cfg )

Thanks,

Rajakiran