1. 5/21/20081 TWAMP (Two Way Active Measurement Protocol) Internet-Draft Overview & Drill Down for PE784 707307b AGN+CORE-Predictive, Proactive, Preventive Mnt -- WIPM Juniper Probe ------------------ Session II -------------- prepared by TJ Wang May 21, 2008

2. 5/21/20082 Recap of Session I TWAMP pronunciation Borrow OWAMP TCP well know port 861 for now; switch when TWAMP ->RFC Unauthenticated mode + (vendor specific) ACL ~ current RTR/SAA implementation Juniper, Cisco, AdTran, WWP are implementing TWAMP Request Session Command Number = 5 Stop Sessions can only be issued by Session Sender (need improve to prevent from hanging the Session Reflector forever) Overview of –Connection Set Up (port, mode, accept, etc) –Connection Commands (request session; start & stop sessionS) –Test Packet Send and Receive Formats – did not have time for this - Today we Drill Down

3. 5/21/20083 Logical Model

4. 5/21/20084 Logical Model

5. 5/21/20085 Connection Setup Client->Server: TCP connection Server->Client: Server Greeting Client->Server: Set-Up-Response Server->Client: Server-Start

6. 5/21/20086 Connection Setup Server Greeting

7. 5/21/20087 Mode of Connection 1 for unauthenticated, 2 for authenticated, and 4 for encrypted. 0 means do not want connect

8. 5/21/20088 Connection Setup Set-Up-Response

9. 5/21/20089 Connection Setup Server-Start

10. 5/21/200810 Values of Accept Field 0 OK. 1 Failure, reason unspecified (catch-all). 2 Internal error. 3 Some aspect of request is not supported. 4 Cannot perform request due to permanent resource limitations. 5 Cannot perform request due to temporary resource limitations.

11. 5/21/200811 TWAMP Control Commands Request-Session, –Client->Server: Create-Session –Server->Client: Accept-Session Start-Sessions, –Client->Server: Start-Sessions –Server->Client: Session-Ack Stop-Sessions –Client->Server: Stop-Sessions or –Server->Client: Stop-Sessions

12. 5/21/200812 Create Test Sessions Request-Session- part 1

13. 5/21/200813 Create Test Sessions Request-Session- part 2

14. 5/21/200814 Create Test Sessions Accept-Session

15. 5/21/200815 Start-Sessions

16. 5/21/200816 Start-Sessions Session-Ack

17. 5/21/200817 Unauthenticated Test Packet Note: TTL MUST = 255 Sequence numbers start with zero and are incremented by one for each subsequent packet.

18. 5/21/200818 Timestamp The format of the timestamp is the same as in [RFC1305] and is as follows: the first 32 bits represent the unsigned integer number of seconds elapsed since 0h on 1 January 1900; the next 32 bits represent the fractional part of a second that has elapsed since then. So, Timestamp is represented as follows:

19. 5/21/200819 Unauthenticated Response Packet

20. 5/21/200820 Stop-Sessions Session-Sender Only 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 3 | Accept | MBZ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Number of Sessions | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MBZ (8 octets) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | HMAC (16 octets) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+