Re: [mpls-tp] Linera Protection - Operator commands terminology.

[Mahesh Akula <[e-mail]>]

Hi Jeong-dong,

Thanks, yes it does clarify the usage of those commands to me.

Regards,
Mahesh

On Wed, Jun 16, 2010 at 3:24 AM, Ryoo, Jeong-dong <[e-mail]> wrote:

> Hi, Mahesh.
>
> Everything you said is ok, except the fact MS is to move the normal traffic
> to the protection path, and MS-W is to move the traffic to the working
> path.FS is to move the traffic to the protection path.
>
> When an operator issues the FS command and removes a node/link in the
> working path, there would be no SF report to the operator or its management
> system. This says that something happening in the working path is due to the
> intentional act of the operator, not by the defect in the working path.
>
> During MS state, if a node/link is removed in the working path, SF will
> occur and the traffic goes to the protection path.
>
> MS-W is for moving the traffic to the working path, and it can be used in
> DNR state or WTR state.
> I hope this can clarify the definition/usage of those commands.
>
> Jeong-dong
>
>     ==============================================
> Jeong-dong Ryoo, Ph.D.
> Principal Member of Research Staff
> Network Research Department
> Electronics and Telecommunications Research Institute (ETRI)
> Phone: [phone], Fax: [phone]
> Email: [e-mail]
> ==============================================
>
> -----Original Message-----
> *From:* "Mahesh Akula" <[e-mail]>
> *From Date:* 2010-06-16 AM 7:54:37
> *To:* "Ryoo, Jeong-dong" <[e-mail]>
> *Cc:* "Weingarten, Yaacov (NSN - IL/Hod HaSharon)" <
> [e-mail]>gt;, "[e-mail]" <[e-mail]>
> *Subject:* Re: Re: [mpls-tp] Linera Protection - Operator commands
> terminology.
>
>
>  Hello Jeong-dong,
>> ?
>> After looking little more into the state transition diagrams in G.8031, I
>> could see the following difference between FS and MS-W.
>> ?
>> If Protection domain is in Forced Switch state, changes in the working
>> path (i.e. SF /SF recovery events) will have no impact on the protection
>> domain state, and recovery path is continued to be used as Active path,
>> unless the recovery path itself goes down or lockout protection/clear
>> commands are triggered.
>> ?
>> Whereas if protection domain is in Manual Switch state,?a series of SF and
>> SF recovery events on the working path will lead to switching the traffic
>> back from recovery path to Working path.
>> ?
>> Is this the expected difference between FS and MS operations?
>> ?
>> If this is not the case, can you pls clarify what is the difference
>> between FS and MS-W as per APS definitions? Also it will be helpful if you
>> can provide the?applicability for these operator commands.
>> ?
>> Regards,
>> Mahesh
>>
>>   On Tue, Jun 15, 2010 at 7:18 AM, Ryoo, Jeong-dong <[e-mail]>wrote;wrote:
>>
>>>  Yaacov,
>>> ?
>>> In my opinion, if there is any technical problem in the
>>> mechanism/protocol,?the problem should be solved.
>>> ?
>>> Besides, the mismatch problem that I stated in my previous?email is
>>> what?G.8031 already?avoids by assigning
>>> different priorities for SF-P and FS.
>>> ?
>>> In the MPLS-TP survivability framework document, the definition of FS
>>> does not have any?consideration on the?defect condition. And the definition
>>> of FS in the MPLS-TP survivability framework document is the SAME as that in
>>> G.8031.
>>> ?
>>> I don't think the behaviour that I stated?violates the architecture.
>>>  ?
>>> Jeong-dong
>>> ?
>>>
>>> ?
>>>     ==============================================
>>> Jeong-dong Ryoo, Ph.D.
>>> Principal Member of Research Staff
>>> Network Research Department
>>> Electronics and Telecommunications Research Institute (ETRI)
>>> Phone: [phone], Fax: [phone]
>>> Email: [e-mail]
>>> ==============================================
>>>
>>> -----Original Message-----
>>> *From:* "Weingarten, Yaacov (NSN - IL/Hod HaSharon)" <
>>> [e-mail]>
>>> *From Date:* 2010-06-15 PM 10:52:21
>>> *To:* "Ryoo, Jeong-dong" <[e-mail]>kr>, "ext Mahesh Akula" <
>>> [e-mail]>gt;, "Adrian Farrel" <[e-mail]>
>>> *Cc:* "Mukund Mani" <[e-mail]>om>, "[e-mail]" <
>>> [e-mail]>
>>>  *Subject:* RE: Re: [mpls-tp] Linera Protection - Operator commands
>>> terminology.
>>>
>>>    Hi,
>>>
>>> ?
>>>
>>> I think that this means that there is a conceptual problem with the
>>> differentiation between the FS and MS commands!? The idea of the difference
>>> that has always been explained is that FS would force a switchover even in
>>> the case of a signal failure ? if as you say that this is not possible
>>> because of the insufficiency of the architecture ? then there is a need to
>>> redesign the architecture or redefine the set of operator commands.
>>>
>>> ?
>>>
>>> BR,
>>>
>>> yaacov
>>>
>>> ?
>>>  ------------------------------
>>>
>>> *From:* ext Ryoo, Jeong-dong [mailto:[e-mail]]
>>> *Sent:* Tuesday, June 15, 2010 16:38
>>> *To:* Weingarten, Yaacov (NSN - IL/Hod HaSharon); ext Mahesh Akula;
>>> Adrian Farrel
>>> *Cc:* Mukund Mani; [e-mail]
>>> *Subject:* RE: Re: [mpls-tp] Linera Protection - Operator commands
>>> terminology.
>>>
>>> ?
>>>
>>> Yaacov,
>>>
>>> ?
>>>
>>> When there is SF on Protection (SF-P),?the Forced Switch (FS)?command
>>> cannot be delivered to?the other end as the APS/PSC protocol message is
>>> conveyed via the protection path.
>>>
>>> As the result, one end is in FS state?and points its selector/bridge to
>>> the protection path
>>>
>>> while?the other end is in SF-P state and points its selector/bridge to
>>> the working path.
>>>
>>> In order to avoid the mismatch, SF-P needs to have a higher priority than
>>> FS.
>>>
>>> ?
>>>
>>> What do you think?
>>>
>>> ?
>>>
>>> Jeong-dong?
>>>
>>>
>>> ?
>>>
>>> ==============================================
>>> Jeong-dong Ryoo, Ph.D.
>>> Principal Member of Research Staff
>>> Network Research Department
>>> Electronics and Telecommunications Research Institute (ETRI)
>>> Phone: [phone], Fax: [phone]
>>> Email: [e-mail]
>>> ==============================================
>>>
>>