- All Implemented Interfaces:
- PCEPElement
public class PCEPOpen
extends PCEPMessage
PCEP OPEN Message (RFC 5440).
From RFC 5440 Section 6.2:
6.2. Open Message
The Open message is a PCEP message sent by a PCC to a PCE and by a
PCE to a PCC in order to establish a PCEP session. The Message-Type
field of the PCEP common header for the Open message is set to 1.
Once the TCP connection has been successfully established, the first
message sent by the PCC to the PCE or by the PCE to the PCC MUST be
an Open message as specified in Appendix A.
Any message received prior to an Open message MUST trigger a protocol
error condition causing a PCErr message to be sent with Error-Type
"PCEP session establishment failure" and Error-value "reception of an
invalid Open message or a non Open message" and the PCEP session
establishment attempt MUST be terminated by closing the TCP
connection.
The Open message is used to establish a PCEP session between the PCEP
peers. During the establishment phase, the PCEP peers exchange
several session characteristics. If both parties agree on such
characteristics, the PCEP session is successfully established.
The format of an Open message is as follows:
::=
The Open message MUST contain exactly one OPEN object (see
Section 7.3).
Various session characteristics are specified within the OPEN object.
Once the TCP connection has been successfully established, the sender
MUST start an initialization timer called OpenWait after the
expiration of which, if no Open message has been received, it sends a
PCErr message and releases the TCP connection (see Appendix A for
details).
Once an Open message has been sent to a PCEP peer, the sender MUST
start an initialization timer called KeepWait after the expiration of
which, if neither a Keepalive message has been received nor a PCErr
message in case of disagreement of the session characteristics, a
PCErr message MUST be sent and the TCP connection MUST be released
(see Appendix A for details).
The OpenWait and KeepWait timers have a fixed value of 1 minute.
Upon the receipt of an Open message, the receiving PCEP peer MUST
determine whether the suggested PCEP session characteristics are
acceptable. If at least one of the characteristics is not acceptable
to the receiving peer, it MUST send an Error message. The Error
message SHOULD also contain the related OPEN object and, for each
unacceptable session parameter, an acceptable parameter value SHOULD
be proposed in the appropriate field of the OPEN object in place of
the originally proposed value. The PCEP peer MAY decide to resend an
Open message with different session characteristics. If a second
Open message is received with the same set of parameters or with
parameters that are still unacceptable, the receiving peer MUST send
an Error message and it MUST immediately close the TCP connection.
Details about error messages can be found in Section 7.15.
Successive retries are permitted, but an implementation SHOULD make
use of an exponential back-off session establishment retry procedure.
If the PCEP session characteristics are acceptable, the receiving
PCEP peer MUST send a Keepalive message (defined in Section 6.3) that
serves as an acknowledgment.
The PCEP session is considered as established once both PCEP peers
have received a Keepalive message from their peer.
- Version:
- 0.1
- Author:
- Oscar Gonzalez de Dios