Stingray Service Gateway with L2 BRAS/BNG supports Framed-Route attribute in Access-Accept response for small (up to /24) subnets. The attribute format is the string "subnet gateway":

   # Canonical format according to RFC 2865 p.5.22 - subnet, gateway and other metrics
   Framed-Route:="192.168.1.0/24 192.168.1.1 1 2 -1 3 400"
 
   # Only subnet and gateway can be specified
   Framed-Route:="192.168.1.0/24 192.168.1.1"
 
   # If the gateway = 0.0.0.0, then Framed-IP-Address is considered a gateway
   Framed-Route:="192.168.1.0/24 0.0.0.0"

You can set no more than 16 attributes Framed-Route in Access-Accept.

All IP-addresses of the specified subnet will be routed through the specified gateway address. This means that gateway IP-address has to be recognized by Stingray Service Gateway - either by authorization (DHCP, ARP, PPPoE), or by setting L2-properties of gateway manually. Also, the gateway IP address must be allocated to the multi-bind subscriber (when authorizing a gateway, the VasExperts-Multi-IP-User=1 attribute must be returned).

SSG saves the routes in the UDR. There are CLI-commands framed route for management.

Framed-IPv6-Route attribute, which sets routing of IPv6-subnet through specified gateway, is processed like IPv4 Framed-Route. Only small subnets are supported (up to /56, or it is better to say up to ipv6_subnetwork - 8):

   # Canonical format according to RFC 3162 p.2.5 - subnet, gateway and other metrics
   Framed-IPv6-Route:="2000:0:0:106::/60 2000::107:a00:20ff:fe99:a998 1"
 
   # Only subnet and gateway can be specified
   Framed-IPv6-Route:="2000:0:0:106::/56 2000::107:a00:20ff:fe99:a998"
 
   # If the gateway = ::, then Framed-IPv6-Address or Framed-IPv6-Prefix is considered a gateway
   Framed-Route:="2000:0:0:106::/56 ::"

Counters for a subnet will be transmitted in total in one gateway accounting session for that subnet. For example, for such a task

   Framed-Route:="192.168.1.0/24 192.168.1.1"

total subnet traffic 192.168.1.0/24 will be taken into consideration in the accounting-session for the gateway 192.168.1.1.