Session Control Manager Overview 
Cisco ASR 5000 Series Product Overview ▄  
  Least Cost, Congestion Based, Call Type, Domain Based 
  As a SIP ALG, supports signaling and media routing with overlapping address ranges 
  SIP Application-level Gateway (SIP-ALG) 
  SIP NAT Traversal 
  SIP NAT (IPv4 <–> IPv6 translation) 
  Media Relay (Header Manipulation): RTP, MSRP 
  Call Admission and Access Control 
  Access Control based on IP, URL, SIP Identity, and Session Limits 
  Topology Hiding Inter-network Gateway (THIG) 
  CALEA Support 
  SIP and media taps 
  SIP Security 
  Prevent Theft of Service 
  Prevent CSCF bypass 
  Robust authentication procedures 
  SIP message checking 
  Prevent Registration Hijacking 
  Authenticate Re-Register (S-CSCF) 
  Early IMS Security: DoS attack prevention, impersonating a server 
  UA authentication (prevent server impersonation) 
  AKA authentication mechanism (further protection) 
  Prevent Message Tampering (IPSec) 
  Prevent Early Session Tear Down 
  Early IMS Security prevents a different user releasing existing session 
  Mitigate SIP Denial of Service (DoS) 
  P-CSCF DoS Attack Prevention 
  Blocking of user/IP address 
  after repeated authentication and bad request failure in Register/INVITE 
  Dropping of Register 
  containing Contact header pointing to CSCF service ip:port 
  Limited number of contacts on which Forking is allowed 
  Dropping of Requests 
  coming from source address other than the Register request's source address