Standardization

1
Standardization

• Henning Schulzrinne
• Dept. of Computer Science
• Columbia University
• Fall 2003

2
Time Line of the Internet

• Source Internet Society

3
Standards

• Mandatory vs. voluntary
• Allowed to use vs. likely to sell
• Example health safety standards ?UL listing
  for electrical appliances, fire codes
• Telecommunications and networking always focus of
  standardization
• 1965 International Telegraph Union (ITU)
• 1956 International Telephone and Telegraph
  Consultative Committee (CCITT)
• Five major organizations
• ITU for lower layers, multimedia collaboration
• IEEE for LAN standards (802.x)
• IETF for network, transport some applications
• W3C for web-related technology (XML, SOAP)
• ISO for media content (MPEG)

4
Who makes the rules? - ITU

• ITU ITU-T (telecom standardization) ITU-R
  (radio) development
• http//www.itu.int
• 14 study groups
• produce Recommendations
• E overall network operation, telephone service
  (E.164)
• G transmission system and media, digital systems
  and networks (G.711)
• H audiovisual and multimedia systems (H.323)
• I integrated services digital network (I.210)
  includes ATM
• V data communications over the telephone network
  (V.24)
• X Data networks and open system communications
• Y Global information infrastructure and internet
  protocol aspects

5
ITU

• Initially, national delegations
• Members state, sector, associate
• Membership fees (gt 10,500 SFr)
• Now, mostly industry groups doing work
• Initially, mostly (international) telephone
  services
• Now, transition from circuit-switched to
  packet-switched universe lower network layers
  (optical)
• Documents cost SFr, but can get three freebies
  for each email address

6
IETF

• IETF (Internet Engineering Task Force)
• see RFC 3233 (Defining the IETF)
• Formed 1986, but earlier predecessor
  organizations (1979-)
• RFCs date back to 1969
• Initially, largely research organizations and
  universities, now mostly RD labs of equipment
  vendors and ISPs
• International, but 2/3 United States
• meetings every four months
• about 300 companies participating in meetings
• but Cisco, Ericsson, Lucent, Nokia, etc. send
  large delegations

7
IETF

• Supposed to be engineering, i.e., translation of
  well-understood technology ? standards
• make choices, ensure interoperability
• reality often not so well defined
• Most development work gets done in working groups
  (WGs)
• specific task, then dissolved (but may last 10
  years)
• typically, small clusters of authors, with large
  peanut gallery
• open mailing list discussion for specific
  problems
• interim meetings (1-2 days) and IETF meetings
  (few hours)
• published as Internet Drafts (I-Ds)
• anybody can publish draft-somebody-my-new-protocol
  
• also official working group documents
  (draft-ietf-wg-)
• versioned (e.g., draft-ietf-avt-rtp-10.txt)
• automatically disappear (expire) after 6 months

8
IETF process

• WG develops ? WG last call ? IETF last call ?
  approval (or not) by IESG ? publication as RFC
• IESG (Internet Engineering Steering Group)
  consists of area directors they vote on
  proposals
• areas applications, general, Internet,
  operations and management, routing, security,
  sub-IP, transport
• Also, Internet Architecture Board (IAB)
• provides architectural guidance
• approves new working groups
• process appeals

9
IETF activities

• general (3) ipr, nomcom, problem
• applications (25) crisp, geopriv, impp, ldapbis,
  lemonade, opes, provreg, simple, tn3270e, usefor,
  vpim, webdav, xmpp
• internet (18) IPv4, IPv6, DNS, DHCP dhc,
  dnsext, ipoib, itrace, mip4, nemo, pana, zeroconf
• oam (22) SNMP, RADIUS, DIAMETER aaa, v6ops,
  netconf,
• routing (13) forces, ospf, ssm, udlr,
• security (18) idwg, ipsec, openpgp, sasl, smime,
  syslog, tls, xmldsig,
• subip (5) layer 2.5 ccamp, ipo, mpls, tewg
• transport (26) avt (RTP), dccp, enum, ieprep,
  iptel, megaco, mmusic (RTSP), nsis, rohc, sip,
  sipping (SIP), spirits, tsvwg

10
RFCs

• Originally, Request for Comment
• now, mostly standards documents that are well
  settled
• published RFCs never change
• always ASCII (plain text), sometimes PostScript
• anybody can submit RFC, but may be delayed by
  review (end run avoidance)
• see April 1 RFCs (RFC 1149, 3251, 3252)
• accessible at http//www.ietf.org/rfc/ and
  http//www.rfc-editor.org/

11
IETF process issues

• Can take several years to publish a standard
• see draft-ietf-problem-issue-statement
• Relies on authors and editors to keep moving
• often, busy people with day jobs ? spurts three
  times a year
• Lots of opportunities for small groups to delay
  things
• Original idea of RFC standards-track progression
• Proposed Standard (PS) kind of works
• Draft Standard (DS) solid, interoperability
  tested (2 interoperable implementations for each
  feature), but not necessarily widely used
• Standard (S) well tested, widely deployed

12
IETF process issues

• Reality very few protocols progress beyond PS
• and some widely-used protocols are only I-Ds
• In addition Informational, Best Current Practice
  (BCP), Experimental, Historic
• Early IETF simple protocols, stand-alone
• TCP, HTTP, DNS, BGP,
• Now systems of protocols, with security,
  management, configuration and scaling
• lots of dependencies ? wait for others to do
  their job

13
Other Internet standards organizations

• ISOC (Internet Society)
• legal umbrella for IETF, development work
• IANA (Internet Assigned Numbers Authority)
• assigns protocol constants
• NANOG (North American Network Operators Group)
  (http//www.nanog.org)
• operational issues
• holds nice workshop with measurement and real
  world papers
• RIPE, ARIN, APNIC
• regional IP address registries ? dole out chunks
  of address space to ISPs
• routing table management

14
ICANN

• Internet Corporation for Assigned Names and
  Numbers
• manages IP address space (at top level)
• DNS top-level domains (TLD)
• ccTLD country codes (.us, .uk, )
• gTLDs (.com, .edu, .gov, .int, .mil, .net, and
  .org)
• uTLD (unsponsored) .biz, .info, .name, and .pro
• sTLD (sponsored) .aero, .coop, and .museum
• actual domains handled by registrars

15
Modern Internet architecture technology

• Advanced Internet Services
• Dept. of Computer Science
• Columbia University
• Henning Schulzrinne
• Fall 2003

16
Internet applications

• Variations on three themes
• distinguish protocol vs. application behavior
• Messaging
• datagram model ? no direct confirmation of final
  receipt
• email (optional confirmation now) and IM
• emphasis on interoperation (SMS, pagers, )
• delays measured in minutes
• Retrieval query (request/response)
• client-server
• ftp, HTTP
• RPC (Sun RPC, DCE, DCOM, Corba, XML-RPC, SOAP)
• emphasis on fast reliable transmission
• delays measured in seconds

17
Internet applications, contd

• Continuous media
• generation rate delivery rate rendering rate
• audio, video, measurements, control
• Internet telephony
• Multimedia conferencing
• related streaming media ?slightly longer
  timescales for rate matching
• video-on-demand
• emphasis is on timely and low-loss delivery ?
  real-time
• delays measured in milliseconds
• focus of this course

18
Internet protocols

• Protocols support these applications
• data delivery
• HTTP, ftp data part, SMTP, IMAP, POP, NFS, SMB,
  RTP
• identifier mapping (id ? id, id ? data)
• ARP, DNS, LDAP
• configuration ( specialized version of
  identifier ? data)
• DHCP, ACAP, SLP, NETCONF, SNMP
• control and setup
• RTSP, SIP, ftp control, RSVP, SNMP, BGP and
  routing protocols
• May be integrated into one protocol or general
  service function (middleware?)

19
Networking is getting into middle years
20
Standardization

• Really two facets of standardization
• public, interoperable description of protocol,
  but possibly many (Tanenbaum)
• reduction to 1-3 common technologies
• LAN Arcnet, tokenring, ATM, FDDI, DQDB, ?
  Ethernet
• WAN IP, X.25, OSI ? IP
• Have reached phase 2 in most cases, with RPC
  (SOAP) and presentation layer (XML) most recent
  'conversions'

21
Technologies at 30 years

• Other technologies at similar maturity level
• air planes 1903 1938 (Stratoliner)
• cars 1876 1908 (Model T)
• analog telephones 1876 1915 (transcontinental
  telephone)
• railroad 1800s -- ?

22
Observations on progress

• 1960s military ? professional ? consumer
• now, often reversed
• Oscillate convergence ? divergence
• continued convergence clearly at physical layer
• niches larger ? support separate networks
• Communications technologies rarely disappear (as
  long as operational cost is low)
• exceptions
• telex, telegram, semaphores ? fax, email
• X.25 OSI, X.400 ? IP, SMTP
• analog cell phones

23
History of networking

• History of networking non-network applications
  migrate
• postal intracompany mail, fax ? email, IM
• broadcast TV, radio
• interactive voice/video communication ? VoIP
• information access ? web, P2P
• disk access ? iSCSI, Fiberchannel-over-IP

24
Network evolution

• Only three modes, now thoroughly explored
• packet/cell-based
• message-based (application data units)
• session-based (circuits)
• Replace specialized networks
• left to do embedded systems
• need cost(CPU network) lt 10
• cars
• industrial (manufacturing) control
• commercial buildings (lighting, HVAC, security
  now LONworks)
• remote controls, light switches
• keys replaced by biometrics

25
New applications

• New bandwidth-intensive applications
• Reality-based networking
• (security) cameras
• Distributed games often require only
  low-bandwidth control information
• current game traffic VoIP
• Computation vs. storage vs. communications
• communications cost has decreased less rapidly
  than storage costs

26
Commercial access cost (T1)
27
Transit cost (OC-3, NY London)
28
Disk storage cost (IDE)
29
Transition of networking

• Maturity ? cost dominates
• can get any number of bits anywhere, but at
  considerable cost and complexity
• casually usable bit density still very low
• Specialized ? commodity
• OPEX ( people) dominates
• installed and run by 'amateurs'
• need low complexity, high reliability

30
Security challenges

• DOS, security attacks ? permissions-based
  communications
• only allow modest rates without asking
• effectively, back to circuit-switched
• Higher-level security services ? more
  application-layer access via gateways, proxies,
• User identity
• problem is not availability, but rather
  over-abundance

31
Scaling

• Scaling is only backbone problem
• Depends on network evolution
• continuing addition of AS to flat space ? deep
  trouble
• additional hierarchy

32
Quality of Service (QoS)

• QoS is meaningless to users
• care about service availability ? reliability
• as more and more value depends on network
  services, can't afford random downtimes

33
Textbook Internet vs. real Internet
34
Textbook Internet vs. real Internet
35
Internet architecture documents (readings)

• http//www.ietf.org/rfc/rfcXXXX.txt
• RFC 1287
• RFC 2101
• RFC 2775
• RFC 3234

36
The Internet Protocol Hourglass(Deering)
37
Why the hourglass architecture?

• Why an internet layer?
• make a bigger network
• global addressing
• virtualize network to isolate end-to-endprotocols
  from network details/changes
• Why a single internet protocol?
• maximize interoperability
• minimize number of service interfaces
• Why a narrow internet protocol?
• assumes least common network functionalityto
  maximize number of usable networks

Deering, 1998
38
Putting on Weight
email WWW phone... SMTP HTTP RTP... TCP
UDP IP mcast QoS ... ethernet PPP CSMA
async sonet... copper fiber radio...

• requires more functionality from underlying
  networks

39
Mid-Life Crisis
email WWW phone... SMTP HTTP RTP... TCP
UDP IP4 IP6 ethernet PPP CSMA
async sonet... copper fiber radio...

• doubles number of service interfaces
• requires changes above below
• major interoper-ability issues

40
Layer splitting

• Traditionally, L2 (link), L3 (network IP), L4
  (transport TCP), L7 (applications)
• Layer 2 Ethernet ? PPPoE (DSL)
• Layer 2.5 MPLS, L2TP
• Layer 3 tunneling (e.g., GPRS)
• Layer 4 UDP RTP
• Layer 7 HTTP real application

41
Layer violations

• Layers offer abstraction ? avoid Internet closed
  for renovation
• Cost of information hiding
• Cost of duplication of information when nothing
  changes
• fundamental design choice of Internet
  difference between circuit and datagram-oriented
  networks
• Assumption packets are large and getting larger
• wrong for games and audio
• Cost prohibitive on wireless networks
• will see 10 bytes of payloads, 40 bytes of
  packet header
• header compression ? compress into state index on
  one link

42
Internet acquires presentation layer

• All learn about OSI 7-layer model
• OSI ASN.1 as common rendering of application
  data structures
• used in LDAP and SNMP (and H.323)
• Internet never really had presentation layer
• approximations common encoding (TLV, RFC 822
  styles)
• Now, XML as the design choice by default

43
Internet acquires session layer

• Originally, meant for data sessions
• Example (not explicit) ftp control connection
• Now, separate data delivery from session setup
• address and application configuration
• deal with mobility
• will see as RTSP, SIP and H.323