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RE: reflections from the trenches of ietf62 wireless

2005-03-17 17:12:32
right now, the folks doing the choosing pretty much have to guess what
the folks doing the using want/need.  open discussion could eliminate
the guessing.

if instead the community feels that reliability for a core set of
functions is paramount, then new features can only be added after they
are viewed as stable and low-risk.

As if the community speaks with one mind...

After the *less than great* wireless deployment for IETF 55 the NOC
team did an internal crit/self crit which you may find interesting -
note the the first thing we talk about is the sometimes conflicting
requirements of the communities of interest:

*disclaimer* these notes are very old - and as all Marlowe fans know
"that was in another country, And besides, the wench is dead."

NOC55 crit/self-crit

Human Factors

 - 4 groups of players/ 4 sets of needs

   - Host
     - responsible for providing the network, user connectivity (wireless
       & TR), t-shirts & any toys, & hosting a Social if there is one.
     - Expect to pay in excess of 100K and order local loop early!
     - Needs:
       - since the host name is attached to network performance, that
         performance needs to be exceptional
       - Given the amount of money & staff time needed, the host should
         expect to be treated like a major donor and given enough
         cooperation to create a positive outcome for everyone.

   - Secretariat/Foretec
     - responsible for booking hotel & arranging room access
     - responsible for power distribution in meeting rooms and
       deployment of power strips for end users
     - hire AV staff & gear
     - on site registration & temp staff
     - all catering for reception/breaks/etc.
.    - manage meeting schedule (agenda & rooms) - communicate needs
       to the host
     - Needs:
       - cost containment?
       - agenda & meeting requirements info from WG's
       - direction from IETF on required services

   - IESG/WG/etc.
     - determine wg agendas & room needs (size, multicast, time frames
       etc.)
     - convey meeting requirements (services, network access, etc.) to
       Foretec
     - additional meetings (ISOC/IAB/IESG)
     - Needs:
       - infrastructure to support the work of the IETF
         (network, power, meeting rooms, AV, lists, multicast, etc.)
       - Support for admin functions (editor, meeting planners, etc.)
       - accurate accounting (revenue generated, admin costs & meeting
         expense) information for decision making.

   - End Users
     - participate in WGs
     - network & TR users require support, need to provide USEFUL feed
       back
     - Needs:
       - infrastructure
       - enough meeting & hotel space
     - Wants:
       - ubiquitous network & power
       - toys & food???

The interests & duties of the four groups overlap and there are some
tensions where those interests compete (i.e.. if the host wants to deploy
a well tested network, the Secretariat wants to keep hotel costs low there
will be scheduling problems that preclude early in-building deployment)

Constraints (55)

 - non-local host
   - no near site space to bench test network elements
 - short time frames for deployment (room access)
   - in building access to the NOC & TR on Friday (network required SAT)
     - early access (Thurs.) to telco space to rack routers & core servers
     - late access to meeting rooms (in some cases just hours before a
       meeting)
http://darkwing.uoregon.edu/~llynch/noc55/mech/11-11-55thMeetingRoomSchedule.html
 - AP selection
   - based on internal factors & lack of support for some Nokia wireless
     cards in the Foretec owned cisco APs. The (16) cisco APs were carried
     as back ups.
   - marginal vendor support for reported problems.
 - Operational "dogfood" (worthy but experimental)
   - dynamic DNS
   - Bro/IDS

Problem Areas

 - Host/Sec communication
 - Noc/End user communication
 - Loss of core staff (Randy/Fenner & then Rob to other duties)

Technical Problems

 - Wireless
   - long story - Joel & Bill?
 - In building infrastructure/switch failure
   - large room wireless failure
   - first mile multicast problems
   Marquis I-IV & the multicast sub-net both ran off two cat5 runs from the
   basement electrical level to the Ballroom control booth on the lobby
   level (3 floors). 2 [8 port] switches were then deployed in the control
   booth and in building cat5 for Marquis was patched. Under load (Mon.
   AM) these switches failed (too long a run?) They were replaced with 24
   port cisco switch (managed) and the problem did not reoccur.
   (Note: heas says "managed is always better")
 - Juniper/DHCP relay issues
   - bug reported, DHCP relay moved to server
 - ARP white noise
   - large amount of arp traffic seen through the routers from turn-up
     never fully diagnosed, but didn't seem to effect performance

Strengths

 - Noc Team depth -
   - Enough folks to cover & second all key roles
 - Fenner & co. (wireless debugging/monitoring)
 - Joel/Cisco AP deployment under stress
 - TR staff
 - excellent volunteer participation (GA Tech & Nokia!)


Lessons Learned

 - choose the best technical solution w/out regard to politics
   - or be prepared to punt if things get messy
 - understand & advertise that running experimental services will lead to
experimental
   NOT production style service.
 - test all existing in building infrastructure under load
   - managed is better at the edge when using other peoples stuff
     (managed is just better)
 - Don't let outside considerations distract from inside problems
   - multicast loss problems lost in the multicast deploy "noise"
 - provide easily accessible data on network status
 - Provide a direct channel for wireless users to help sort info

Nits

 - more communications tools may not be better...
   (list/web/RT/radios/cell phones etc.)
 - NOC needs faster access to changes on the host page, or a nested NOC
   page (user updates, publicizing monitoring data, etc.)

Needed in Future:

 - better information about how & when wireless worked at past IETFs
   (I suspect it worked when there were many fewer users)
 - A "WiNUrs" BOF (Wireless Network Users) at either NANOG or IETF
   - w/ a clinic to demonstrate dense deployment issues
     (attractive nodes/sticky nodes/adhoc users/overloading failures/
      association refused/etc.)
   - & user education & tools
     - meetings need a quick report mechanism that reports:
       user mac address|OS (version)|card type & driver|settings
       & an FAQ of known problems.
     - users continue to send clear text passwords (Fenner data)

Lucy E. Lynch                           Academic User Services
Computing Center                        University of Oregon
llynch  @darkwing.uoregon.edu           (541) 346-1774

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