Hi Reshad, thank you for providing the context to BFD Echo TX. Indeed, I'm familiar with implementations that use BFD Echo as Echo request/reply and thus Tx would be in RPC, not in configuration. I think that it would be good to discuss this in Chicago unless we hear comments from others on the list.
Regards, Greg On Mon, Feb 27, 2017 at 5:56 AM, Reshad Rahman (rrahman) <[email protected]> wrote: > Hi Greg, > > draft-zheng-mpls-ls-ping-yang-cfg defines transmit interval in RPC > because all ping operations are done via RPC. I do not consider BFD echo > to be “on demand” like LSP Ping (caveat: this is possibly due to the BFD > configuration/implementation I am most familiar with). > > Regards, > Reshad. > > From: Greg Mirsky <[email protected]> > Date: Monday, February 27, 2017 at 1:07 AM > To: Mahesh Jethanandani <[email protected]> > Cc: Reshad <[email protected]>, "[email protected]" <[email protected]>, " > [email protected]" <[email protected]> > Subject: Re: Correcting BFD Echo model > > Hi Mahesh, > BFD Echo transmit interval is not part of RFC 5880, only Rx interval is. > And Rx interval is sufficent to reflect whether local system is willing to > receive BFD Echo messages from the particular BFD peer. Introduced > desired-min-echo-tx-interval functionally overlaps with the > standard-defined required-min-echo-rx-interval. Hence my suggestion to > remove desired-min-echo-tx-interval from grouping > bfd-grouping-echo-cfg-parms. But operators need a way to specify transmit > interval for on-demand OAM command like BFD Echo, IP ping or LSP ping. I > couldn't find YANG model proposal for IP ping but in > draft-zheng-mpls-lsp-ping-yang-cfg transmit interval used in RPC, not as > part of configuration. > > Regards, > Greg > > > On Sun, Feb 26, 2017 at 8:33 PM, Mahesh Jethanandani < > [email protected]> wrote: > >> >> On Feb 26, 2017, at 4:39 PM, Greg Mirsky <[email protected]> wrote: >> >> Hi Reshad, >> thank you for the question. Here's my reasoning: >> >> - only Required Min Echo RX Interval is present in RFC 5880 and it >> allows to indicate not only the smallest interval between consecutive BFD >> Echo packets but whether system supports BFD Echo function at all; >> - since BFD Echo may be transmitted only when the session state is >> Up, operator is fully equipped to learn the value of Required Min Echo RX >> Interval of its BFD peer and to set Echo transmit interval accordingly; >> - requesting BFD Echo, in my opinion, is no different from requesting >> IP ping or LSP ping. >> >> Hence my conclusion - transmit interval for BFD Echo is more suitable in >> RPC then as configuration parameter. >> >> >> I do not think that is reason enough for it to be a RPC. >> >> A RPC is an operation one defines in the YANG model specifying both input >> and output parameters. There are no operations to be had here. >> >> And the definition and desired behavior of desired-min-echo-tx-interval >> is not very different from required-min-echo-x-interval. It is as the >> definition says, a configuration parameter that can be set, with zero >> having a special meaning in both cases. >> >> >> Regards, >> Greg >> >> On Sun, Feb 26, 2017 at 2:52 PM, Reshad Rahman (rrahman) < >> [email protected]> wrote: >> >>> Hi Greg, >>> >>> Can you please explain why you believe this should go in RPC? >>> >>> Regards, >>> Reshad. >>> >>> From: Greg Mirsky <[email protected]> >>> Date: Saturday, February 25, 2017 at 6:48 PM >>> To: "[email protected]" <[email protected]>, "[email protected]" >>> <[email protected]> >>> Subject: Correcting BFD Echo model >>> Resent-From: <[email protected]> >>> Resent-To: <[email protected]>, Reshad <[email protected]>, < >>> [email protected]>, <[email protected]>, < >>> [email protected]> >>> Resent-Date: Saturday, February 25, 2017 at 6:48 PM >>> >>> Dear All, >>> I've reviewed the BFD YANG model and now I'm thinking that >>> desired-min-echo-tx-interval >>> and attributing to it the behavior, i.e. when the value is 0, of Required >>> Min Echo RX Interval are not in the right place. I think that definition of >>> desired transmit interval of BFD Echo should be in corresponding RPC >>> definition, not in configuration part of the model. >>> Appreciate your comments. >>> >>> Regards, >>> Greg >>> >> >> >> >
