Hi Quintin,
Following up with some more detail on top of Dan's email.
>> The draft is very good and is helpful coordinate PCE and TE technologies
>> between applications and network. I focused on some sections and have
>> following questions and suggestions.
Thanks for reading and commenting.
Answers in line.
>> (1) Applicability of ABNO Architecture.
>> Your document abstract and introduction discusses scenarios including
>> content and data-center interconnection ("Services such as content
>> distribution, distributed databases, or inter-data center connectivity
>> place a set of new requirements on the operation of networks."). I
>> think the architecture is also relevant to lots of other environments:
>> mobile backhaul, core transport, packet switch network, etc. Do you
>> agree?
>
> DK>> Yes, thats true. We did focus on the data center applicability as
> we presented some slides at MPLS Washington 2012 which discussed
> that specific scenario and the draft followed some of the same language.
I agree. We were trying to describe some service environments rather than
network environments, and we certainly don't want to imply any limitations on
the uses or the network environments. We expect that the architecture could be
used in a whole range of applications: both at the static end of the spectrum
(such as mobile backhaul), and for more dynamic services.
We will highlight this point in the next revision.
>> (2) ABNO Controller.
>> Section 2.2.13 (ABNO controller) needs to be discussed in more detail.
>> Do you think multiple ABNO controllers or just one ABNO controller
>> will be required? Maybe an implementation will use a ABNO Controller
>> per "application" (Service Coordinator/NMS/OSS)?
>
> DK>> When we were white boarding and discussing the architecture we
> certainly considered that a number of the ABNO components would require
> multiple instances per deployment, including the ABNO Controller. As per
> your next point we will try to be more specific in the ABNO text.
>
>> (3) PCE or PCE's?
>> Figure 1 shows *a* PCE. It is expected that multiple PCE' would be used,
>> this is important for VNTM Use Case. Maybe you can show more PCE's
>> in the figure 1 or describe it?
>
> DK>> As Above, yes.
As Dan says, there can certainly be multiple instances of the functional
components in the figure. This could arise within an implementation to
load-share, provide specialist capabilities (as you suggest for the ABNO
Controller), to maintain confidentiality or separation of function (as you
suggest for PCE), or to distribute the function across platforms. We are keen to
stress that this is a functional architecture, not an implementation road-map. I
think we will add a section on "Implementation of the Architecture" to discuss
these points.
>> (4) Network Resiliency.
>> I am interested in ABNO managing network failures that may be
>> protected with shared mesh protection at the network which could
>> be MPLS TP or WDM. ABNO would provide a shared path protection
>> which optimizes as network conditions change. This is based on
>> client layer requirements of reliability and protection restoration
>> time. To make this possible the shared mesh protection paths would
>> need to be client layer traffic aware and have customer SLA
>> information. Do you think this is a good use case?
>
> DK>> Cool. I think this could represent quite a complex multi-layer
> optimization problem. Please let Adrian and me have more
> information on the scenario. Ideally documenting the various
> component functions (specific for the use case) and each
> component interaction, again with some detail on what information
> needs provided and perhaps propose protocol mechanism or
> extensions. Think of the draft as a tool kit. We would like to reuse
> existing technology as much as possible. The use case should reflect
> this.
Yes, this sounds like an interesting use case. Shared mesh protection (and also
1:n protection) can be a complex provisioning problem, and changes in services
as well as changes in network availability can require significant dynamic
reassessment of the placement of LSPs. If you would like to suggest text for a
use case, I think we would be happy to see it.
>> (5) Custom (Abstracted) Topologies.
>> Could ABNO provide abstracted topologies via the north-bound
>> interface to the requester (provisioning tool)? In China we have
>> the customers who would like IPv6 deployment in IPv4 backbone.
>> If provider can assign specific nodes and links to be used for
>> logically isolated IPv6 plane, then the ABNO (I2RS and BGP-LS)
>> architecture could be used to provide abstracted topology based
>> on the preferred equipment for carrying tunneled IPv6 traffic. Is
>> this another use case that may be useful?
>
> DK>>Maybe we can focus on the SMP use case first. This use case
> might benefit from some of the discussion Young raised yesterday,
> in terms of the virtual topology presentation.
Actually, I think the model already supports exporting information from the TED
as described in Section 2.2.2.4. This section does not clearly explain that the
TED could be "abstracted", but it should! We will add some text.
>> (6) Manageability and Security.
>> Are you going to provide Manageability and Security sections in
>> future versions of the ABNO document or another document?
>> It is an important area for ABNO that needs further discussion.
>
> DK>> We will most definitely include some discussion in the ABNO
> framework, along with policy.
Agreed. (Unless someone else writes the text first :-)
Thanks,
Adrian
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