In one embodiment, excess committed network appliance resources are shared for providing services within a network appliance. One approach maintains service resources in a committed service resource pool and one or more other pools of service resources. Service resources are taken from a corresponding pool as needed. Service resources are reallocated to the committed resource pool as needed to ensure that service resources are available to service corresponding packet streams at their corresponding committed rate. Examples of such services provided by a network appliance include, but are not limited to, network address translation (NAT), firewall, Internet Protocol Security (IPsec), virtual private network (VPN), or deep packet inspection (DPI) services.