In simple terms, DHCP determines if your IP is static or dynamic and the length of time an IP address is assigned. Dynamic Host Configuration Protocol is controlled by a DHCP server. Your router can be a DHCP server...and if you're on a home network, it most likely serves this purpose.
Researchers report that the average adolescent needs eight and a half to nine and a half hours of sleep each night. But in a poll taken in 2006 by the National Sleep Foundation, less than 20 percent reported getting that much rest on school nights.
So how much is the right amount of sleep? The new guidelines not only give recommended amounts, but also state what might be appropriate for different ages. Children aged six to nine need nine to 11 hours a night, but may get by on seven to eight. Teenagers need eight to 10 hours. Seven hours may be OK for some, but sleeping more than 11 hours a day may be detrimental to their health, although some may need that much during puberty.