- All Implemented Interfaces:
- PCEPElement
public class PCEPKeepalive
extends PCEPMessage
PCEP Keepalive Message (RFC 5440).
From RFC 5440, Section 6.3
6.3. Keepalive Message
A Keepalive message is a PCEP message sent by a PCC or a PCE in order
to keep the session in active state. The Keepalive message is also
used in response to an Open message to acknowledge that an Open
message has been received and that the PCEP session characteristics
are acceptable. The Message-Type field of the PCEP common header for
the Keepalive message is set to 2. The Keepalive message does not
contain any object.
PCEP has its own keepalive mechanism used to ensure the liveness of
the PCEP session. This requires the determination of the frequency
at which each PCEP peer sends Keepalive messages. Asymmetric values
may be chosen; thus, there is no constraint mandating the use of
identical keepalive frequencies by both PCEP peers. The DeadTimer is
defined as the period of time after the expiration of which a PCEP
peer declares the session down if no PCEP message has been received
(Keepalive or any other PCEP message); thus, any PCEP message acts as
a Keepalive message. Similarly, there are no constraints mandating
the use of identical DeadTimers by both PCEP peers. The minimum
Keepalive timer value is 1 second. Deployments SHOULD consider
carefully the impact of using low values for the Keepalive timer as
these might not give rise to the expected results in periods of
temporary network instability.
Keepalive messages are sent at the frequency specified in the OPEN
object carried within an Open message according to the rules
specified in Section 7.3. Because any PCEP message may serve as
Keepalive, an implementation may either decide to send Keepalive
messages at fixed intervals regardless of whether other PCEP messages
might have been sent since the last sent Keepalive message, or may
decide to differ the sending of the next Keepalive message based on
the time at which the last PCEP message (other than Keepalive) was
sent.
Note that sending Keepalive messages to keep the session alive is
optional, and PCEP peers may decide not to send Keepalive messages
once the PCEP session is established; in which case, the peer that
does not receive Keepalive messages does not expect to receive them
and MUST NOT declare the session as inactive.
The format of a Keepalive message is as follows:
::=
- Version:
- 0.1
- Author:
- Oscar Gonzalez de Dios