HP Velocity functional overview | Establishing a connection |
Beaconing
Once an HP Velocity-enabled endpoint detects that a bidirectional network path is available, it periodically modifies packet headers (both IP and TCP) in a seamless way to advertise itself to other HP Velocity-enabled endpoints (Figure 2).
IP headers can contain both IP ID-based beacons (using an option value of 0x420B) and IP Option-based beacons (using an option value of 0x880477FB). TCP flows can use TCP Option-based beacons (using an option value of 0x01 No-Operation and seven sets of End of Option Lists 00000000000000).
Once an HP Velocity-enabled endpoint processes enough beacons on a network flow to discover that another HP Velocity-enabled endpoint is at the other end, handshaking occurs.
NOTE: The use of TCP Option-based beacons for TCP flows and IP
Option-based beacons for UDP flows can be controlled through the
HP Velocity Policy Engine.
Figure 2. IPQ beaconing
Handshaking
An HP Velocity-enabled endpoint will initiate a three-way handshaking procedure with an HP Velocity-enabled endpoint discovered during beaconing. Once the handshake is completed, both HP Velocity-enabled endpoints enter the protected state.
Protected state
In the protected state, HP Velocity-enabled endpoints exchange information about current and trending network conditions. This information is then used to intelligently activate and adjust various optimizers.
HP Velocity Server Side Deployment Guide | 10 |