RE: [EFM] Active to active connections are useful
To expand on what Matt stated, the two modes active and passive are for
different implementation/service models.
Active mode would be for enterprise users that want to manage their own
implementation services as peer to peer facilities. This functions similar
to the current model of enterprise LAN and dedicated MAN implementation
models in which the fiber/copper facility is either directly owned by the
"user" or is in a dedicated lease to the "user". In this model, it is
unlikely that a $ubscription service provider would take part of the OAM
The passive mode would be for $ubscription packet services (such as IP
based application services) from a service provider or over a service
provider owned facility. In this model, it would normally be the service
provider end systems that are "managing" the customer end systems and the
link between. With this model, the customer is restricted to monitoring
their own systems without access to the service provider systems. This is
the way that $ubscription services are normally managed and is required for
the ability to support the customer service link and provide a level of
security to the service provider and other customers.
As you can see, without the passive (asymmetric) mode, the objective to
provide support for $ubscription services would not be met. The active
(symmetric) mode is provided to be backward compatible with the existing
At 04:19 AM 9/18/03 -0400, Matt Squire wrote:
>OAM has two provisioned modes - active and passive. Active is intended
>for those devices that wish to query/control their peer in some
>respect. Passive is intended for those that do not wish to query/control,
>but will respond.
>OAM can be provisioned to be symmetric (e.g. active-active as John
>mentioned), or not (active-passive). Both deployment models (symmetric,
>asymmetric) have been requested and determiend to have merit, and both can
> > -----Original Message-----
> > From: Tom Mathey, Gail McCoy [mailto:firstname.lastname@example.org]
> > Sent: Thursday, September 18, 2003 6:40 AM
> > To: email@example.com; John Messenger; Alan Weissberger
> > Subject: Re: [EFM] Active to active connections are useful
> > John,
> > I must admit to not following the Clause 57 OAM very closely.
> > However, from the reading that I have done, I certainly was under the
> > assumption that the OAM capability was symmetric. That is, the
> > customer can perform any and all OAM actions. The CPE end was no
> > different from the CO end. A customer must be able to test their
> > connectivity to the CO. If this is not permitted, then the draft
> > must change. Do you need any support on this for the next draft?
> > You must not be at the Italy meeting.
> > A copy to Alan as he is interested in OAM.
> > NOTE: You need to modify your e-mail settings as the private message
> > that I tried to send on this same subject bounced with the following
> > reply:
> > ----- The following addresses had permanent fatal errors -----
> > <firstname.lastname@example.org.>
> > (reason: 550 5.7.1 This system has been configured to
> > reject your mail)
> > Tom
> > >Hi,
> > >
> > >I read the comments about "local_satisfied" in the proposed
> > resolutions
> > >(#594, #679) and I agree that it would be helpful to include
> > diagnostics
> > >about why discovery won't complete. However it raises a
> > couple of issues:
> > >
> > >1. The ability to initiate a loopback from the CPE to the CO
> > is useful for
> > >commissioning. This requires the CPE to be in Active mode.
> > (Just because
> > >you let the other end be Active doesn't mean you have to support his
> > >Variable Requests.) I'd be interested to know whether
> > switch vendors intend
> > >to support OAM loopback paths for this purpose?
> > >
> > >2. I anticipate implementations that propose their favoured
> > configuration
> > >and see if it is acceptable to the other end, but if it is not
> > >(local_satisfed remains false after a few cycles of
> > discovery) then back off
> > >to a less-favoured but still operable configuration. For
> > example a CPE
> > >might propose to be active and if that was not OK, back off
> > to proposing to
> > >be passive. As we do not specify the behaviour of the OAM
> > Client, this is a
> > >point that implementors need to bear in mind - discovery should be a
> > >negotiation, not a "take it or leave it" conversation.
> > >
> > >If anyone would be willing to summarise the resolution at
> > the interim for
> > >me, I'd be grateful.
> > >
> > > -- John
> > >--
> > >John Messenger (JMessenger@advaoptical.com)
> > >R&D Software Manager, ADVA Optical Networking Ltd.
> > >Tel: +44-1904 699309 Fax: +44-1904 699378
> > >www.advaoptical.com
> > >"Mind like parachute - only work when open" (Charlie Chan)
> > --