Transcript Why eduroam sucks, and how to fix it.

Why eduroam sucks,
and how to fix it.
Josh Howlett, UKERNA.
TNC 2007, Copenhagen.
eduroam
doesn’t
suck
eduroam rocks!
• it is one of the best ideas in academic
networking in years.
• hundreds of Institutions already support it.
• it is revolutionising network service
delivery.
“So what’s this talk about?”
Outline
• eduroam has become a victim of its own
success.
• explain the challenges.
• discuss how these are being addressed.
• I am not here to evangalise!
The ‘growing pains’ of eduroam
1. eduroam relies on some
poorly implemented
technologies.
2. eduroam also relies on
other technologies that
weren’t designed for what
eduroam is trying to
achieve.
3. good policy is hard.
Gartner hype-cycle 2006
eduroam in a slide
Supplicant
Authenticator
(AP or switch)
RADIUS server
RADIUS server
User
DB
University A
Guest
University B
Network
piet@university_b.nl
Employee
VLAN
Commercial
VLAN
Central RADIUS
Student
VLAN
Proxy server
•
Trust based on RADIUS plus policy
documents
signalling
•
802.1X
data
•
(VLAN assigment)
User
DB
Windows
sucks
(Windows’ supplicant, at least…)
Why Windows’ supplicant sucks
• Limited authentication options
– EAP-TLS (user certificates suck)
– EAP-PEAP (MS-CHAP sucks)
• Can’t authenticate against ‘hidden’ SSIDs
• Passwords cached in the registry
• The default configuration settings
– ~20 steps to implement a good configuration.
– ~4 sides of A4 including screenshots.
How we’re trying to fix it
• Our pain is the supplicant industry’s gain
– Some good but costly commercial supplicants
• Open source supplicants (Windows)
– SecureW2
• An EAP-TTLS plug-in for the Windows supplicant
• Addresses some of the problems, but not all.
– Open1x project
• Port of Xsupplicant to Windows
• Managed by OpenSEA Alliance (Extreme Networks, Identity
Engines, Infoblox, Symantec Corporation, TippingPoint,
Trapeze Networks and UKERNA)
PKI
sucks
(for wireless authentication…)
Why PKI sucks
• The only available secure EAP methods
depend on PKI
– No one understands PKI, least of all users.
– Certificates rooted to CAs in Windows cost €.
• Certificate-based TLS handshake is highly
verbose
– Authentication is slow and fragile over a lossy
network.
How we’re trying to fix it
• TERENA Server Certificate Service
– Another excellent initiative from TERENA
• Proposed shared-secret methods
– EAP-TLS-PSK
– EAP-GPSK
• Use a reliable transport for EAP (more
later)
RADIUS
sucks
(…or RADIUS wasn’t designed for this!)
Why RADIUS sucks
• eduroam is pushing RADIUS’ capabilities.
– Routing is bound to the DNS hierarchy
• Who should manage .org, .edu or .net?
– ukerna.ac.uk is changing to ja.net…
– Hierarchical routing is fragile and slow
• EAP-PEAP: ~ 10-15 round-trips @ ~ 250ms RTT (~2-4 sec)
• ~ 2-5% packet loss
• Retransmission driven by RADIUS server (3-5 sec timeouts)
– Poor support for inter-domain authorisation
• user attributes are exposed to proxy servers
• RADIUS attributes are relatively inflexible (cf. SAML).
How we’re trying to fix it
• Routing
– RADSec
• RADIUS over TLS over TCP.
• Unlikely to gain traction in IETF.
– Diameter
• IETF’s proposed successor to RADIUS.
• Only one commercial implementation.
– We need PKI for both...
• Authorisation
– DAMe (GN JRA5)
– RADIUS-SAML (Internet2 FWNA)
– Perhaps we’re trying to be too clever?
• Would a small set of RADIUS attributes be sufficient to cover
our use-cases?
Inconsistent
policy sucks
Why inconsistent policy sucks
• Visible Services, Transparent Networks
• Consistency matters
– Reduces costs and user satisfaction.
• eduroam confederation policy
– “[Institutions] SHOULD provide open network access”
– Great idea, but will the ‘SHOULD’ be ignored?
• If tcp/80 is the only common denominator then in practice
eduroam becomes interweb only.
• eduroam has competitors
– Commercial 802.11, GRPS, UMTS, 802.16, 802.20…
How we’re trying to fix it
• Opinions differ 
– 26 NRENs, 100s Institutions…
• How should policy be balanced between
Institutions, NRENs and confederation?
– Perhaps we need more experience?
• I carry about a GPRS/UMTS dongle; a
sign of things to come?
• Do we need to add more value?
Conclusions
• Most Institutions can deploy eduroam without
problems today.
• There are technology issues for some
Institutions, but we’re close to fixing these.
• There are scaling issues, but these will be fixed
in the medium term.
– This is not an excuse for delaying joining!
• The confederation policy may need some minor
adjustments, but nothing significant.
• De we need to add more value?
Thank you for your attention
• Any questions?