Oscar F' Palomino

1
TDC477 Network Security I
VoIP NETWORK THREATS

• Oscar F. Palomino

2
Attack and Security in VoIP

• SIP
• SIP terminals, SIP Server (Proxy, Redirecter,
  Registar)

• H.323
• Gateway, Gatekeeper, H.323 terminal

3
Attacks in VoIP

• Flood DoS and DDoS
• Large amount of random messages from a single
  (DoS) or multiple locations (DDoS)
• Degrade or crash system, resources, denying
  services
• Also sending a CANCEL or BYE message to end call

4
Attacks in VoIP (cont)

• Call Hijacking
• Hijack session replace registration with its own
  address. Manipulation of registration records
• Misuse/abuse Toll fraud. Free calls to outside
  destinations

5
Security in VoIP (cont..)

• Authentication/authorization different entities
  client server (TSL)
• Encryption protect the content of packets from
  being read by other parties.
• Apply encryption selectively

6
Security in VoIP (cont..)

• VLANs
• Against DoS, Separates by logically voice and
  data segments