Hi, I'm looking at r08 sections 6.3 and 7.2.
Section 6.3 has Note that sending Keepalive messages to maintain the session alive is optional and PCEP peers may decide to not send Keepalive messages once the PCEP session is established. Section 7.2 has Keepalive (8 bits): maximum period of time (in seconds) between the sending of PCEP messages. The minimum value for the Keepalive is 1 second. When set to 0, once the session is established, no further Keepalive messages need to be sent to the remote peer. And also A sends an Open message to B with Keepalive=10 seconds and Deadtimer=30 seconds. This means that A sends Keepalive messages (or ay other PCEP message) to B every 30 seconds and B can declare the PCEP session with A down if no PCEP has been received from A. I find this peculiar. Sending a keepalive message does not verify for the sender that the session is open. It verifies for the receiver. So, surely the parameter in the Open object says how frequently the sender of the Open message wants to receive a Keepalive message. That is, how often the receiver of the Open message must send a Keepalive message. For example, if a PCC is worried that the session may fail, it will want to operate the keepalive process. But as currently specified, the PCC can only tell the PCE how often the PCC will send Keepalive messages, and after what period the PCE may declare the session dead. This is no help to the PCC! If the PCE decides that it will not send Keepalive messages then the PCC cannot determine the health of the session and cannot switch to a new PCE. In other words, the keepalive process is back-to-front. Further, I don't see why you need the keepalive timer value and the dead timer value. One value can be derived from the other, probably through a recommended ratio of 3.5. Lastly, when describing that the use of keepalive is optional, there are a couple of points: 1. Optional should be an RFC 2119 word 2. You need to make it clear that it is not the "PCEP peers" that decide to not send keepalives, but "each PCEP peer" that decides "whether it wants to receive keepalives" 3. You should indicate the circumstances surrounding the choice for this option. I think that, you might suggest that if PCE discovery is in use, the failure of a PCE can be speedily detected by the failure of the IGP, and can be flooded by timing out the LSA containing the discovery information. In this case, keepalive would not be needed. Yes? Adrian _______________________________________________ Pce mailing list [email protected] https://www1.ietf.org/mailman/listinfo/pce
