State Machine

This table provides information about the UPF states.

States Machine

S.No.

Previous State

Internal Fault

C-R BFD

C-C BFD

SRP Link State

Next State

Pull Down BFD

1

X

Yes

X

X

X

Standby

Yes

2

X

X

Any-Down

X

X

Standby

Yes

3

X

No

All-Up

Any-Down

X

Active

No

4

X

No

All-Up

All-Up

Down

No-Change

No

5

X

No

All-Up

All-Up

Up

SRP-Protocol

-Decided

No

NOTES:

  • For C-R BFDs going from "Not-All-Up" to "All-Up", a delay is introduced in SRP State processing to allow all C-C BFDs to reach steady state.

  • To avoid the dual-active scenario, ensure that the states in row 3 of the above table do not occur in both UPFs. This must not happen in a properly functioning and configured system.