Voice over IP Fundamentals

1. CHAPTER 13 • Gateway Control Protocols Voice over IP Fundamentals

2. Media Gateway Control Protocol: • MGC: Media Gateway Controller • MG: Media Gateway • Master/Slave relationship • MG handles: • Time-division Multiplexing (TDM)into Real-time Transport Protocol (RTP)/Real-time Transport Control Protocol (RTCP) • Intelligence resides in the MGC • MGC handles all call signaling • MGCP messages carried by User Datagram Protocol

3. Media Gateway Control Protocol: • Uses Session Description Protocol (SDP) to describe media sessions • Call agents use SDP to provision endpoints with: • IP Addresses • UDP port • Audio media: (Specifies audio media and codec)

4. Media Gateway Control Protocol:

5. Media Gateway Control Protocol: • Endpoints can either Sink or Source data • Endpoints are identified by an endpoint identifier • Domain Name • Local Name • Connections are either point-to-point or multipoint • Commands are composed of a command and a mandatory response • <Command name><Transaction-ID><Endpoint-ID><MGCP ver>

6. Media Gateway Control Protocol: • Basic Call Control Commands: • Create Connection (CRCX) • Modify Connection (MDCX) • Delete Connection (DLCX) • Advanced Call Control Commands: • Notification request (RQNT) • Notification (NTFY) • Management Commands • Audit Connection (AUCX) • Audit Endpoint (AUEP) • Restart in Progress (RSIP) • Endpoint Configuration (EPCF)

7. Media Gateway Control Protocol: • Create Connection (CRCX) • Call ID: Unique Call Identifier • Notify Entity (N): Where to send notifications • Local Connection Options (L): Encoding, Packetization, Bandwidth, Type of Service…. • Mode (M): Full duplex, Receive only, Send only, Inactive and Loopback • Remote Connection Description (RC): Connection description for the remote side

8. Media Gateway Control Protocol: • Modify Connection (MDCX) • Encoding Scheme • Packetization Period • Echo Cancellation • Connection Activation • Connection Deactivation

9. Media Gateway Control Protocol: • Delete Connection (DLCX) • Terminates a Connection • Places the endpoint into Inactive mode • Provides Statistical Information

10. Media Gateway Control Protocol: • Notification Request (RQNT) • Request Events (R) • Fax and Modem Tones • Continuity Tones and Detection • On-hook and Off-hook Transition • Flash hook • Channel-associated Signaling (CAS) • Wink • DTMF

11. Media Gateway Control Protocol: • Notification Request (RQNT) • Signal Requests (S) • Ringing • Distinctive Ring • Ring Back • Dial • Intercept • Busy • Answer • Call Waiting • Off-hook warning • Continuity tones

12. Media Gateway Control Protocol: • Notification Request (RQNT) • Signal Requests (S) Tones: • On/Off (OO) • Time-out (TO) • Brief (BR)

13. Media Gateway Control Protocol: • Notification Request (RQNT) • Signal Requests (S) Tones:

14. Media Gateway Control Protocol: • Notification Request (RQNT) • Notification Entity (N): Where to send notifications • Request Identifier (X): Correlates the Notification Request with the notification

15. Media Gateway Control Protocol: • Notification (NTFY) • Notified Entity (N): Where to send notification • Request Identifier (X): Correlates the request to the notification • Observed Events (O): List of events that the gateway detected

16. Media Gateway Control Protocol: • Audit Endpoint (AUEP) • Endpoint List: Identifies the endpoint • Notify Entity (N): Whom to notify • Requested Events (R):List of currently requested events • Digit Map • Signal Request (S): List of currently applied signal requests • Request Identifier (X): Identification for the last Notify Request received • Connection Identifier (I): Current connections for an endpoint • Detect Events (T): Currently detected events in Quarantine mode • Local Connection Options (L): A list of current values

17. Media Gateway Control Protocol: • Audit Connection (AUCX) • Call ID: Unique Identifier to the call • Notify Entity (N): Whom to notify • Local Connection Options (L): Options currently being applied • Mode (M): Current mode of the connection • Remote Connection Descriptor (RC): The remote SDP being used • Local Connection Descriptor (LC): Gateway used for the connection • Connection Parameters (P): Current value of parameters at the audited connection

18. Media Gateway Control Protocol: • Restart In-Progress (RSIP) • Endpoint ID: Unique Identifier • Restart Method (RM) • Graceful • Forced • Restart • Disconnected • Restart Delay (RD): Delay in seconds

19. Media Gateway Control Protocol: • Endpoint Configuration (EPCF) • Specify the encoding of signals • International circumstances that use both u-law and a-law • Bearer Information (B): Identifies encoding technique

20. Media Gateway Control Protocol: • Response Messages

21. Media Gateway Control Protocol: • Response Messages

22. Media Gateway Control Protocol: • Call Flows Basic

23. Media Gateway Control Protocol: • Call Flows Trunking

24. Media Gateway Control Protocol: • Advanced MGCP Features • Events and event packages • Digit Maps • Embedded Notification Requests • Non-IP bearer networks

25. Media Gateway Control Protocol: • Event Packages Basic

26. Media Gateway Control Protocol: • Event Packages Endpoint

27. Media Gateway Control Protocol: • Digit Maps • Collects digit events (dialed) • Digit-by-digit • RQNT • NTFY

28. Media Gateway Control Protocol: • Embedded Notifications Requests • R:hd(E(R[0-9]))

29. End of Chapter 13