E2M - State Machine
- Avinoam Bernstein
| Document status | DRAFT |
|---|---|
| Document owner | |
| Owner Details | +972-54-2891166, ab600d@intl.att.com |
RAN States
E2M supports the following state for each RAN:
| State | Description |
|---|---|
| Null | No RAN in DB |
| Disconnected | Either the connection failed, E2T dies or E2T initialized |
| Connected | Remote RAN sends Setup Request |
| Shutting-Down | Temporary state during Red Button (From Dashboard) |
| Shut-Down | Persistent state after Red Button (From Dashboard) |
RAN Events
We have the following events which might change SM:
- Setup Request from RAN
- Connection failed from E2T
- E2T Initialized - E2T Restart (New E2T or existing)
- Red Button (From Dashboard)
- Keep Alive (KA) in E2M discover E2T isn't responding
RAN State Machine - States vs. Events
RM = Resource Management
States ==> Events | Null | Disconnected | Connected | Shutting-Down | Shut-Down |
|---|---|---|---|---|---|
Setup Request from RAN | Connected; Update RM; Send Setup Response; | Update RM; Disconnect- | Connected; (See note below) Update RM; Send Setup Response; | Ignore | Connected; Update RM; Send Setup Response; |
SCTP Failure (Lost Connection) | Error | Error | Disconnect; Update RM; | Shut-down | Error |
E2 Initialize | Ignore | Update RM; Disconnect- | |||
Red Button | Shut-down | Shutting-Down; Tear down connection to E2T | Error | ||
KA discover E2T dies | Ignore | Disconnect; Update RM; |
Note
Flow of Setup -
- Assuming Success parsing the message (Else - Error)
- Update DB - RAN Name, RAN ID, Data in the Setup Request payload (Functions), State = Connected, E2T Address - Assuming DB write succeed Else - Error)
- If update RM is OK (Associate RAN to E2T Address)
- Send Setup Response.
- If RMR failure - Error but don't Roll back
- Else (RM Failure)
- Can't send RAN any message (Even Setup Failure isn't possible)
- Leave RAN as connected and associated to E2T Address
- When RM will initialized and query E2M, it will distribute the RMR to all RIC.
In case Setup Request in Connected State - Update DB (it might be different), Update RM (it might be even different E2T in rare scenario), Return Setup Response.
Flow charts in the RAN State
State = Null (RAN doesn't exist in DB)
State = Connected
State = Disconnected
State = Shutting Down
State = Shut Down
