[Nsi-wg] Service Termination Points
Jerry Sobieski
jerry at nordu.net
Mon Mar 14 11:28:58 CDT 2011
Hmm...maybe I am confused... (not often:-)
What hop by hop aspects are we speaking to?
J
On 3/14/11 12:21 PM, Inder Monga wrote:
> Returning the hop-by-hop capabilities does not necessarily imply walking the tree.
>
>
> Inder
>
> On Mar 14, 2011, at 7:50 AM, Jerry Sobieski wrote:
>
>> I think we had agreed at GLIF that queries would be (for now) just
>> returning the PA's state and the request parameters as-built. That
>> there was no walking the tree implied at this time...?
>>
>> J
>>
>> On 3/13/11 12:29 PM, John MacAuley wrote:
>>> If we remove the hop-by-hop capabilities from the reservation request, do I also remove it from any queries?
>>>
>>> On 2011-03-13, at 1:06 PM, Chin Guok wrote:
>>>
>>>> I'm fine just specifying the source and destination in the initial implementation. However I think that as we evolve the protocol, being able to specify "mid-point" STPs will be useful.
>>>>
>>>> If I recall correctly, the issue was that the end user may not be able to see the "mid-point" STPs and thus is unable to verify the path. However as we start adding other services (i.e. monitoring, etc), lack of visibility may not be an issue.
>>>>
>>>> - Chin
>>>>
>>>> --On March 12, 2011 11:51:20 PM -0500 John MacAuley<john.macauley at surfnet.nl> wrote:
>>>>
>>>>> I am okay not to specify anything other than the source and destination,
>>>>> but was this not the whole discussion around not routing traffic through
>>>>> certain locations by specifying the route? It resulted in the trust
>>>>> discussion.
>>>>>
>>>>>
>>>>> Does anyone else have strong opinions on the topic?
>>>>>
>>>>>
>>>>> John.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 2011-03-12, at 11:42 PM, Jerry Sobieski wrote:
>>>>>
>>>>>
>>>>> Hi John-
>>>>> I know we've had long discussions about path objects. But I am not so
>>>>> sure they are necessary...
>>>>>
>>>>> If we can make two concatenated connections and treat them as one, then
>>>>> why do we need to specify loose hops?
>>>>> We can instead just issue two reservation requests, right? If so, this
>>>>> would substantially simplify the request structure. And so far, I've not
>>>>> heard of any use case that multiple reservations would not work for
>>>>> transit routing.
>>>>>
>>>>> ??
>>>>>
>>>>> Jerry
>>>>>
>>>>>
>>>>> On 3/12/11 10:35 PM, John MacAuley wrote:
>>>>>
>>>>>
>>>>> Taking Jerry's definition and Tomohiro's note not to use domain or
>>>>> endpoint I have defined the following three XML schema components:
>>>>>
>>>>>
>>>>>
>>>>> • A "Path Object Type" consists of at a minimum an "aSTP" and a
>>>>> "zSTP", with an optional ordered list of "STP" defining the path through
>>>>> the network.
>>>>> • An "STP Type" consisting of a mandatory "Network Id" string and a
>>>>> mandatory "Local Id" string that uniquely identify the STP. There is an
>>>>> optional "Order" attribute that will only be populated when the STP is
>>>>> part of the ordered list.
>>>>> • An "STP List Type" that will support both an ordered and unordered
>>>>> list of STPs.
>>>>>
>>>>>
>>>>>
>>>>> So is does my definition of a Path Object cover what was intended in the
>>>>> CS architecture document?
>>>>>
>>>>>
>>>>> <xsd:complexType name="PathObjectType">
>>>>> <xsd:sequence>
>>>>> <xsd:element name="aSTP" type="tns:StpType" minOccurs="1"
>>>>> maxOccurs="1" />
>>>>> <xsd:element name="orderedStpList" type="tns:StpListType" />
>>>>> <xsd:element name="zSTP" type="tns:StpType" minOccurs="1"
>>>>> maxOccurs="1" />
>>>>> </xsd:sequence>
>>>>> </xsd:complexType>
>>>>>
>>>>> <xsd:complexType name="StpType">
>>>>> <xsd:sequence>
>>>>> <xsd:element name="networkId" type="xsd:string" minOccurs="1"
>>>>> maxOccurs="1" />
>>>>> <xsd:element name="localId" type="xsd:string" minOccurs="1"
>>>>> maxOccurs="1" />
>>>>> </xsd:sequence>
>>>>> <xsd:attribute name="order" type="xsd:integer" />
>>>>> </xsd:complexType>
>>>>>
>>>>> <xsd:complexType name="StpListType">
>>>>> <xsd:sequence>
>>>>> <xsd:element name="stp" type="tns:StpType" minOccurs="0"
>>>>> maxOccurs="unbounded" />
>>>>> </xsd:sequence>
>>>>> </xsd:complexType>
>>>>>
>>>>>
>>>>>
>>>>> On 2011-03-12, at 10:11 PM, Jerry Sobieski wrote:
>>>>>
>>>>>
>>>>> Hi John-
>>>>>
>>>>> Yes. For NSI I think we can say an STP==endpoint.
>>>>>
>>>>> I think STPs in the abstract sense may be topological locations other
>>>>> than just a port or a VLAN, but for the purposes of NSI v1.0, I think a
>>>>> "real STP" is indeed a location in the topology where a connection may
>>>>> originate or terminate.
>>>>>
>>>>> (I note that I used a circular reference in the endpoint definition.
>>>>> Apologies. An Endpoint is the physical topological terminus of a
>>>>> connection.) I do reserve some flexibility in the abstraction
>>>>> however. I think there are ways we can use Service Termination Points to
>>>>> indicate larger complexes of topological elements. If folks are
>>>>> intersted I will elaborate, but for now, and to be expedient with respect
>>>>> to defining ReserveRequest() parameters, I suggest we accept an adequate
>>>>> definition and leave additional refinement to later.
>>>>>
>>>>> Is this helpful?
>>>>> Jerry
>>>>>
>>>>> On 3/12/11 9:57 PM, John MacAuley wrote:
>>>>>
>>>>> Jerry,
>>>>>
>>>>>
>>>>> So based on your definition below is STP == Endpoint Reference from an
>>>>> NSI protocol perspective?
>>>>>
>>>>> Definitions:
>>>>>
>>>>> Service Termination Point := 1. An abstract object that represents the
>>>>> ingress or egress point of a connection, or the abstract notion of a
>>>>> location in a topology where a connection could potentially originate or
>>>>> terminate. 2. A real point in a topology where a connection can
>>>>> originate or terminate.
>>>>>
>>>>> Endpoint := In NSI, this is a location within a network that can be used
>>>>> as an endpoint for a connection.
>>>>>
>>>>> Endpoint Reference := a two-tuple consisting of a {<network name>,
>>>>> <endpoint name>} . An “endpoint reference” is this tuple, the
>>>>> “endpoint” itself is the topological location it identifies.
>>>>>
>>>>> John.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>> _______________________________________________
>> nsi-wg mailing list
>> nsi-wg at ogf.org
>> http://www.ogf.org/mailman/listinfo/nsi-wg
> ---
> Inder Monga
> imonga at es.net
>
>
>
More information about the nsi-wg
mailing list