Subject: Re: [vnfpool] Great effort

From: "Susan Hares" <[email-masked]>
Date: Sun, 15 Dec 2013 20:52:38 -0500

Richard and Melinda:

In an effort to review carefully Ning, Linda, and Melinda's draft - I wanted
to re-engage with a few points on your earlier posts.   The VNF pools have
scope beyond just the network service provider generic usage.  The VNF pools
can be used in the vertical markets in medical, financial, and
mobile-stores.  

I apologize that I am coming in late to the discussion. Rather than create a
new post for all my questions, I've found some original posts, and I am
commenting on these posts.  

I'd like to pick up the discussion of Richard's questions on the post below:

.         is there any reference (sub-ms, 10s ms) on the requirement of
latency for the back-up devices (e.g. firewall) to take over? 

Short answer: Yes, the medical, financial, and mobile-store applications can
require a latency for back-up devices that is sub-ms, 10s ms.  It depends on
the device and applications.  I will start with medical examples below.
Financial and mobile-store applications later (if I am on track). 

.         What is the persistency requirement regarding NF state recover: no
loss because master state is not recoverable or the state is reconstructable
and fast recover is just an optimization? 

Short answer:  No loss is important in medical crisis/critical/urgent data
so that it is auditable what data got delivered when.  (Medical care is
audited in the US due to insurance).  In other portions of the applications
fast-recover that reconstructs is possible.  

This need sets the adaptability requirements for the VNF Pools. 

Please see  gets into Section 3.5 section of Dreibholz, Tuxen, Shore, Zong
document on RSerPool for Virtual Network Function Resource Pooling
(draft-dreibholz-vnf-pool-rserpool-applic-00.txt) especially in the pool
member selection in adaptive strategies or over-provisioning with
non-adaptive strategies.   ADARA's product does have sub-second adaptive
strategies that condition the VRF pools deployed in medical, financial (E.g.
stock trades/Quick loans approvals),  and mobile-store scenarios. 

Context for my comments: 

Let me give an example of a few markets in which the whole process has
time-critical nature: medical, financial, and mobile store.  Let me start
with medical.  I will add additional posts on financial and mobile. 

Medical devices exist with hospitals at all levels.  If you visit a
top-ranked US hospital you will find that he Doctors and nurses are carrying
mobile devices that allow them to access patient results, patent records,
and surgical information.  Doctors may communicate within a single hospital
or a multi-building complex or within the hospitals within a metro Area. For
example the University of Michigan (U of M) Hospital is a single hospital
with over 30 buildings.  It exists in Ann Arbor with 3 other research
hospitals that are the same size, and within the Detroit Metro-Area with 20+
other large hospitals.  Doctors within Ann Arbor may be consulting on
patience within Ann Arbor or the Detroit Area.  Patients come from the
regional area which includes the Canadian city of Windsor plus around the US
for the advance treatment. 

The medical traffic has several priorities: 

.         Crisis alerts for Doctors, 

.         Critical information needed to alert doctors on patient care,

.         Urgent important information on consultations needed for urgent
patient care, 

.         Medical records of a recent test that Doctors have flagged for
updates, 

.         Doctor's notes on patient visits;

.         Nurses chart information on patient vital signs or 

.         Medical financial records on charges due to the patient,

.         Medical insurance records (payments and coverage), and 

.         Social services on patient care needed. 

In this environment, by US law medical information must be kept secure,
confidential and private.  It must not travel to certain geographical
boundaries (E.g. not outside United States).  The medical traffic ranges
from short texts to massive files for medical images.  

VNF pools need to handle the firewall, load-balance, WAN acceleration,
traffic monitoring, and SPAN/TAP at some level.   However, the key important
that seems to be lost is the understanding that these functions need to be
application aware.  

For example, the most important thing for the Doctor's Crisis alerts is that
the application that informs the doctors and/or nurses on-call has the
necessary things to get the information to the doctor, and provide
receive/response times for the medical audit. This crisis alert may be used
in the surgical post-operation system or in the emergency ward.  The
Wireless/Wired system can have requirements for 10ms set-up of VNF.  Fast
Adaptability is key. 

After the alert for the medical information, the system may spin up VMs with
VRF functions to provide the critical information and then provide quick
reference to massive amounts of data is also necessary.  It may be that the
most important thing to transfer to the Doctor iPad is the key medical test
information along with patient data.  Data may come from multiple hospitals
in multiple networks to a Virtual applications on some server. 

You can see that the Firewall, LB, WAN Acceleration, and Traffic Monitoring,
SPAN/TAP are just a few things that the networking system must track. 

Impact on the Reliable VNF Problem statement:

-          VNF on page 5 states: failures of hardware, status change
(over-utilization, network congestion), software failure (VM, VNF I
nstance), performance downgrade (contention between VNF instances), and
instance migration due to software instance. 

All of these are great, and should be handled at every layer of the stack
(physical, link, network, transport, and application). 

The question is how do you have vertical applications which know certain
things about the stack influences changes.  How do we do this and keep
secure? 

Please let me know if there are reasonable questions or if I have missed
something in the discussion. 

Sue Hares 

 

From: [email-masked] [mailto:[email-masked]] On Behalf
Of Y. Richard Yang
Sent: Wednesday, September 18, 2013 12:14 AM
To: Melinda Shore
Cc: [email-masked]
Subject: Re: [vnfpool] Great effort

Hi Melinda,

On Tuesday, September 17, 2013, Melinda Shore wrote:

On 9/17/13 7:32 PM, Y. Richard Yang wrote:
> zookeeper may not be limited to client-server. It is a service for a
> pool of other servers to coordinate, for example, to elect the next
> meta server.

Hi, Richard:

I am not previously familiar with Zookeeper so I may be
misunderstanding something fundamental, but it seems to
me from what I've read that Zookeeper may not be
suitable for HA applications, in that it may not meet
performance requirements. In this case "distributed
synchronization" means something more closely aligned
with, say, rsync than with keeping stateful network
devices in sync.  If you think about, say, a firewall
in a service provider network, do you think that
Zookeeper is suitable for moving firewall-associated
state from one device to another within extremely
constrained elapsed time requirements?  

Good question.

Is there any reference (sub-ms, 10s ms, ...) on the requirement of latency 

for a backup device (e.g., firewal) to take over? What is the persistency
requirement

regarding NF state recovery: no loss because master state is not recoverable

or the state is reconstructable and fast recovery is just an optimization?

Richard

To me it looks
more like a network configuration platform.

Melinda
_______________________________________________
vnfpool mailing list
[email-masked] <javascript:;> 
https://www.ietf.org/mailman/listinfo/vnfpool