Subject: bgp18 WG Last Call fsm missing next state

From: "Tom Petch" <[email-masked]>
Date: Thu, 28 Nov 2002 14:53:56 -0000

In seven places in the FSM, the actions listed for the occurrence of
an event do not include any indication of what the next state should
be, nor can I be sure I can guess what it should be.

I believe the FSM should specify the new state in the cases listed
below.

      Connect State:

        If the TCP connection succeeds [Event 15 or
        Event 16], the local system checks the "Delay Open
        Flag".  If the delay Open flag is set, the local system:
**enters what state

        If the TCP connection receives an indication
        that is invalid or unconfigured. [Event 14]:
**enters what state

      Active State:

        A TCP connection succeeds [Event 15 or Event 16], the
        local system: process the TCP connection flags
         - If the BGP delay open flag is set:
** enters what state (I think this is an FSM error in TCP because it
has not initiated a connection!)

        If the local system receives a valid TCP Indication
        [Event 13], the local system processes the TCP connection
flags.
** enters what state

        If the local system receives a TCP indication
        that is invalid for this connection [Event 14]:
** enters what state

        If the local system receives a TCP connection
        failed [Event 17] (timeout or receives connection
        disconnect), the local system will:
** enters what state

      Open Confirm State:

        If the Open messages is valid [Event 18], the collision
        detect function is processed per section 6.8.  If this
        connection is to be dropped due to call collision, the
        local system:
** enters what state

Tom Petch
[email-masked]

---

From: Jeffrey Haas <[email-masked]>
Date: Fri, 29 Nov 2002 20:33:14 -0500

Tom,

>         Flag".  If the delay Open flag is set, the local system:

Remains in the connect state awaiting either an open message or
for the opendelay timer to expire.

>         that is invalid or unconfigured. [Event 14]:

Enters the active state.
Connectretrytimer should be started.

> has not initiated a connection!)

In the active state, we are awaiting incoming tcp connections to be
completed.  Here we should:

remain in the active state
wait for an open message or the opendelay timer to expire.

>         [Event 13], the local system processes the TCP connection

I'm also confused by this event.  Since we are not initiating a TCP
connection, but are awaiting one to complete, why would we get an
Indication here?  FSM error?

>         that is invalid for this connection [Event 14]:

Ditto.

>         disconnect), the local system will:

Ditto.

>         connection is to be dropped due to call collision, the

This instance of the FSM should be discarded since it implies there is
another FSM instance running that will proceed to Established?

-- 
Jeff Haas 
NextHop Technologies