[c-nsp] ip subscriber dhcp help

[Mike]

Hi,

     I'm working thru trying to set up a new asr1000 for subscriber 
service and I'm having trouble understanding how to incorporate dhcp 
based subscribers into my radius-based architecture.

     I have the following interface config:

interface GigabitEthernet0/0/0.120400
  description xxxx - Subscriber DHCP
  encapsulation dot1Q 400 second-dot1q 12
  ip dhcp relay information trusted
  ip dhcp relay information policy-action keep
  ip address 172.16.128.1 255.255.255.0
  ip helper-address 10.0.16.198
  ip subscriber l2-connected
   initiator dhcp
end


     I can issue a dhcp request on a client connected to that interface 
and the whole dhcp relay process works correctly and an ip is allocated 
and assigned to the client. I can also "sh ip subscriber detailed" and 
the router has in fact created an ip subscriber session too:


IP subscriber: xxxx.xxxx.xxxx, type connected, status up
   display uid: 406, aaa uid: 419
   segment id: 4193, session hdl: 0x2C000008, shdb: 0x2000196
   session initiator: dhcp discovery
   access interface: GigabitEthernet0/0/0.120400
   access address: 172.16.128.2
   service address: 172.16.128.2
   conditional debug flag: 0x0
   control plane state: connected, start time: 00:15:54
   data plane state: connected, start time: 00:15:54
   arp entry: 172.16.128.2, GigabitEthernet0/0/0.120400
   forwarding statistics:
     packets total: received 0, sent 0
     bytes total: received 0, sent 0
     packets dropped: 0, bytes dropped: 0
   hardware forwarding statistics:
     packets total: received 92, sent 0
     bytes total: received 40287, sent 0

     Ok so the basics are out of the way. My question now is - how do I 
assign subscriber profile attributes from my radius, and how do I get 
the router to give me accounting statistics for these sessions? I'm 
looking to achieve parity with PPPoE based subscribers where I stuff all 
the required bits into the access-accept message with Cisco-AVPair 
attributes for example. DHCP has no such function (?) so theres no way 
to return anything other than dhcp messages like netmask, ip address and 
name servers. I've been staring at the cisco ISG guides for a long time 
and am throughly confused. Does anyone have an easy/simple example or 
explanation?

Thank you.

Mike-