Transcript kevin
Looking in EARNEST for future directions in
European Research and Education Networking
APAN 26
6 August 2008, Queenstown, New Zealand
EARNEST Background
› Part of EU-funded GN2 (GÉANT2) project involving 35 NRENs.
› Aims to identify trends, developments, and to make
recommendations for future research and education
networks.
› Seven sub-studies:
› Organisational and Governance issues
› Economic issues (move to dark fibre, and provision of new
services)
› Researchers’ needs (what type of network and services are
required?)
› Other users’ needs (e.g. schools, healthcare, arts & humanities)
› Geographic issues (examining and quantifying digital divide)
› Campus issues (infrastructure, services, expertise and
collaboration)
› Technical issues (transmission, control plane & routing,
network virtualisation, operations and performance,
middleware)
Slide 2
Methodology & Caveats
› Technical panel with expertise in specific areas advised on
important or emerging technologies.
› Interviews with key personnel from 11 vendors, 3 research
institutes, and a number of NRENs.
› Technological briefings and research papers also used.
› Primary goal was to investigate technologies applicable to
NRENs, although attempts to address other types of network
as well.
› R&E networks often have different requirements to telco and
ISP sectors, and usually have fewer legacy issues.
› Focused on four (later five) general areas…
Slide 3
Transmission Technology Findings
Slide 4
Ethernet or SDH?
› No obvious path for SDH beyond OC-768 (40 Gbps), and
likely to become legacy technology in coming years.
› All manufacturers developing 40 and/or 100 Gigabit Ethernet
because of cost advantages, and because packet-based
services are increasingly prevalent.
› Was initially expected that 100 GE would be next standard,
but this is proving to be technically difficult.
› Not expected before 2010.
› Initially likely to be 4 x 25 Gbps.
› 40 GE may be interim solution, and offered at 40% of cost of
OC-768.
Slide 5
Ethernet Enhancements
› Ethernet scalability initially addressed with IEEE 802.1Q and
802.1ad.
› PBB (IEEE 802.1ah) aims to greatly increase number of
customer networks, and defines protocols for connecting
provider-bridged networks.
› Carrier-grade OAM&P and virtual circuit functionality is also
currently being added:
› PBBTE (802.1Qay) will support point-to-point circuits over
Ethernet.
› CFM (802.1ag) will support hop-by-hop detection, isolation of
connectivity problems
› Shortest-Path Bridging (IEEE 802.1aq) being developed as
alternative to Spanning Tree for loop-free forwarding.
http://www.terena.org/activities/ngn-ws/ws1/docs/061107-jacobsTERENA-NGN-WS-01.pdf
Slide 6
DWDM Systems
› Trade-off between number of wavelengths, faster line rates
and longer reaches due to CD, PMD, XPM and FWM.
› New modulation techniques (e.g. DP-QPSK) are becoming
practical and promise longer reaches at 40 Gbps+ speeds,
whilst minimising need for EDCM.
› Most manufacturers focusing on 50 GHz spacing for DWDM
channels (i.e. ~80 channels per fibre). This has been found
to provide optimal performance with respect to faster line
rates and longer reaches.
› Tunable lasers, VOAs, EDCMs, multi-degree ROADM
technology, and PIC-based OEOs promise easier-to-facilitate
(and potentially cheaper) DWDM systems. Also make
meshed optical networks possible.
Slide 7
DWDM Systems
› Questions to ponder:
› There was a lot of hype about DWDM five years ago, but
actually how important is this to NRENs?
› Dark fibre is increasingly available to NRENs, but few fully
exploit DWDM possibilities.
› Why is the take-up of DWDM by NRENs so slow?
› Is being ‘faster’ or ‘fatter’ more important to NRENs?
Slide 8
Control Plane & Routing Findings
Slide 9
IP Routing
› Routing scalability becoming problematic (again).
› Global routing table now >230,000 entries, which generates
around 400,000 BGP updates per day.
› Concern that growth is starting to outstrip router chipset and
memory developments, but more specifically the cost of
provisioning these.
› IPv6 doesn’t help as end-users unwilling to use provider-assigned
addresses, or renumber when changing service providers.
› Not immediate cause for concern, but IAB/IETF looking for
efficiencies.
› Multihoming and traffic engineering should be possible.
› Addresses should be provider-independent
› Proposals based on splitting IP addresses into unique
identifier (EID) and provider-dependent locator (RLOC).
Slide 10
IPv6
› Core IPv6 specifications and related protocols largely
completed some years ago.
› Most NRENs already support IPv6 in dual-stack systems, but
also tend to have more IPv4 address space.
› Some router and user equipment still has limited support.
› Still limited support in most campuses.
› New predictions suggest IPv4 address space could be
exhausted in 3-5 years.
› Regional Internet Registries discussing rationing measures.
Slide 11
Network Virtualisation Findings
Slide 12
Network Virtualisation
› Virtualisation concepts starting to be used across all
networking layers.
› Basic virtualisation already implemented in certain modern
routers to enable upgrades and troubleshooting of specific
interfaces, and programmable features.
› NRENs (e.g. CANARIE, CESNET) pioneered customerempowered network concept, where resources on NRENprovisioned infrastructure can be managed by customers to
build logical networks.
› Deployment of UCLP, DRAC and similar technologies are first
step towards full network virtualisation.
› Need for technology agnostic infrastructure, although most
users still want IP connectivity as part of service.
Slide 13
Network Virtualisation
› MANTICORE and FEDERICA projects aim to develop network
virtualisation to allow disruptive technologies to be tested
over production infrastructure.
› US-based GENI initiative extends concept to wireless and
sensor networks as well.
› EARNEST study revealed there was little knowledge in wider
R&E community about virtualisation initiatives, but lot of
potential interest.
› TERENA NGN Workshop (06/11/07) had session on network
virtualisation/customer-empowered networks.
› Generated much discussion.
› Support for information exchange and coordination activity (e.g.
task force).
› Need a better term to describe all this though!
Slide 14
Operations & Performance Findings
Slide 15
Layer 0-2 Management
› NRENs have traditionally only managed Layer 3 and above,
so have limited experience at the optical level (WDM systems
and/or SDH).
› Limited tools for managing Network Layers 0-2, and
expensive.
› Although some R&E developments such as TL1 Toolkit and NDL.
› Management of Layers 0-2 is currently labour intensive and
relies heavily on documentation.
› NRENs have not really made extensive use of WDM systems
to-date, and the management of much so-called dark fibre is
often outsourced.
› Is this something to investigate further?
Slide 16
Overprovisioning vs QoS
› Core networks likely to continue to be overprovisioned as
bandwidth is (relatively) cheap.
› Some edge networks do need to undertake traffic
engineering though, so QoS transparency should be
supported.
› Increasing availability of dark fibre allows R&E networks to
operate hybrid networks, enabling dedicated links to be
provisioned for demanding customers using C/DWDM.
› Should encourage innovation through network neutrality,
subject to traffic engineering requirements.
Slide 17
End-to-End Connectivity
› Most end-to-end performance issues are due to problems at
customer sites.
› Middleboxes such firewalls, NATs, rate shapers, caches and
other ‘black box’ solutions are responsible for many of these
problems.
› This is due to instrinic architecture, misconfigurations, or simply
intentional behaviour.
› They encourage workarounds that circumvent what the box is
trying to achieve in the first place.
› Consider improving network transparency, either through
protocol support, or moving functionality closer to end-hosts.
› Filtering and firewalling should also be weighed against reduction
in innovation capabilities within research environment.
› Buggy or sub-optimally tuned software also responsible for
some problems (e.g. TCP stacks for large file transfers).
› Consider evolution of PERT concept.
Slide 18
Middleware Findings
Slide 19
Identity Federations
› Identity federations are solution for supporting user
access to remote services.
› Most NRENs have identity federation or are
establishing one. Others should plan to do so within
next couple of years.
› NRENs are natural candidates for supporting technical
organisation within their countries, as well as
representing national federations.
› User-centric identity (e.g. OpenId) management also
growing, and abstract identity framework also being
worked on. NRENs should monitor developments.
› Already integrations of identity federation and OpenId
Slide 20
Interoperability
› Inter-operability of identity federation happening:
› SAML 2.0 is today choice for exchanging identity data for web-based
applications.
› All the identity federations technologies are SAML2.0-compatible or
they migrating to be SAML2.0-compatible.
› Schemas such as eduPerson or SCHAC becoming more important to
facilitate inter-operability.
› In order to be able to handle different AAIs it is recommended
that NRENs support multiple trust infrastructures:
› X.509 certificates used quite a lot.
› SAML signed tokens, coming up.
› It is recommended that NRENs try to minimise number
necessary (e.g. by reusing existing PKIs).
› Still open issue: No well established standard for communicating
identity data to applications.
› NRENs should be proactive about this (possible task force?)
Slide 21
Further Information
› EARNEST Reports
› http://www.terena.org/activities/earnest/publications.html
› TERENA NGN Workshops
› http://www.terena.org/activities/ngn-ws/
› Thanks to:
Alcatel-Lucent, Calient, Ciena, Cisco, DTU-COM, DANTE, Extreme
Networks, Force10, i2CAT, IBM, Juniper, Liberty Alliance, MERLIN
Project, Nortel, Sun Microsystems & SxIP
plus the Advisory Panellists
Slide 22