Naming and addressing in Future Internet

Transcription

1 Naming and addressing in Future Internet 서울대학교유태완

2 Contents Introduction Background Historical point of view Candidate solutions Evolutionary Approach Revolutionary Approach Conclusion 2

3 Introduction Historical consideration for Naming, addressing, and routing Problems Time goes on: Internet growing large Problems Approaches Toward to Future Internet Candidate solutions 3

4 Naming, Addressing, and Routing General definition [IEN #19] The 'name' of a resource indicates *what* we seek, an 'address' indicates *where* it is, and a 'route' tells us *how to get there*. [IEN#19] John F. Shoch, A note on Inter-Network Naming, Addressing, and Routing, Internet Experiment Note #19, Jan

5 Naming, Addressing, and Routing Name is a symbol, usually a human-readable string identify processes, places, people, machines, functions, or anything else the user chooses To be useful, however, there will probably be some mechanism available to the user that will map names into addresses Address is the data structure whose format can be recognized by all elements in the domain, and which defines the fundamental addressable object. At the time one wishes to communicate with a particular address, there will be some mechanism that will map an address into an appropriate route. Route is the specific information needed to forward a piece of information to its specified address. When the path to an address requires several steps (as in a store and forward system), the route defines a path through intermediate switching points. a *name* may be used to derive an *address*, which may then be used to derive a *route*. 5

6 Naming and Binding [RFC1498] Problem Confusing for concepts Need to more well-defined form for their names Define four terms borrowed from OS Service and Users: These are the functions that one uses, and the clients that use them. Nodes: These are computers that can run services or user programs. Network attachment points: These are the ports of a network, the places where a node is attached. The term "address" is an identifier of a network attachment point. Paths: These run between network attachment points, traversing forwarding nodes and communication links. Binding: process of mapping a name to an address Services/users to node: DNS Node to NAP: DHCP NAP to Path: ARP [RFC1498] J. Saltzer, On the Naming and Binding of Network Destinations, IETF RFC 1498, Aug

7 Current Internet Applying terms MAC addresses: identifies a layer-2 interface IP addresses: used for host-to-host data delivery! Mapping to MAC address: ARP DNS names: used by applications Mapping to IP address (in addition to other things): DNS service! Port number: used to identify application processes Problems [John Day] The only identifier we have for anything is the IP address There are no node addresses and no application names [John Day] John Day, "Things They Never Taught You About Naming and Addressing," AsiaFI WIFI workshop, feb. 2010, Korea 7

8 Problems Mostly regarding IP address usage [Lixia Zhang] IP address: identifies an attachment point of an IP node for data delivery But also used by TCP as connection identifier, or even by some applications as node identifier TCP connection breaks when data changes incoming interface, or Host changes IP address! When a TCP connection broke, application on top of it broke too [Lixia Zhang] Lixia Zhang, " The Evolving Process of Name space & Identifers in the Internet Architecture," AsiaFI WIFI workshop, feb. 2010, Korea 8

9 Growing Internet New demands on old naming Site multihoming Host multihoming Mobility NAT Securing host-host communications Make the architecture meet the new needs Exactly what problems we need to solve For existing name space IP address: what can and should it be used for DNS names: what can and should it be used for? What new name space do we need? 9

10 Approaches Follow Internet History Why The Internet Only Just Works [M. Handley] Solutions that have actually been deployed in the Internet core seem to have been developed just in time, perhaps because only then is the incentive strong enough. In short, the Internet has at many stages in its evolution only just worked. Challenge for obtaining new opportunities Fundamentally design new architecture Clean-slate based designing [M. Handley] Mark Handley, Why The Internet Only Just Works, BT Technology Journal, Vol 24, No 3, July

11 Scalability and ID/LOC separation

12 Problem: BGP Table Growth #2 Scaling Problems #1 Scaling Problems From bgp.potaroo.net/cidr/ 12

13 #1 Scaling Problems Recognition of exponential growth late 1980s CLNS as IP replacement December, 1990 IETF ROAD group and the three trucks Running out of class-b network numbers Explosive growth of the default-free routing table Eventual exhaustion of 32-bit address space Two efforts short-term vs. long-term More at The Long and Winding ROAD 13

14 Approach Scaling issues in the early 1990 s Accelerate Internet growth by the invention of the Web RFC 1287 Towards the Future Internet Architecture Published in December Define Problems In IP environment, running out of addresses (address shortage) In Routing space, running out of capacity (routing scalability) Some approaches by planned solution Short (Interim) term approach Remove class-based semantics, instead use explicitly specified prefix length RFC 1518 An Architecture for IP Address Allocation with published in 1993 CIDR (Classless Inter-Domain Routing) Long term approach Make new protocol to extend address space -> IP Version 6 14

15 #2 Scaling Problems Growing concern about scaling, transparency, multihoming, renumbering, provider independence, traffic engineering, IPv6 impact ( ) IAB Routing & Addressing workshop (2006) Published RAW Report (analysis scaling problems) RFC 4984 Report from the IAB workshop on Routing and Addressing R&A Directorate established IRTF - Routing Research Group recharter R&A discussion list active (ram@iab.org) 15

16 Broken Scalability by [RFC4984] Provider Independent Assigned (PI) They never have to renumber, they keep their PI addresses forever The Internet is doing flat site-based routing Multihoming Injects more-specific routes from one provider to another which the entire global routing table must then carry Traffic engineering Inject more-specific routes to influence the behavior of the routing system, in order to contorl various traffic patterns [RFC4984] D. Meyer et at all, Report from the IAB Workshop on Routing and Addressing, IETF RFC4984 Dec,

17 Scalable Design For routing to scale, locators need to be assigned according to topology and change as topology changes ( Addressing can follow topology or topology can follow addressing; choose one Y. Rekhter) But as identifiers, assignment is along organizational hierarchy and stability is needed users and applications don t want renumbering when network attachment points change 17

18 ID/LOC split ID/LOC split from IP address space ID Global unique Topology independency Flat is better Persistency till session survival time LOC Globally routable Topology dependence Dynamically change Binding Dynamically bind btw. ID and LOCs 18

19 ID-LOC separation Application Connect to example.etri.re.kr Application Transport Connect to id: id: :110::1 Transport ID-LOC separation IP Packet to 2001:110::1 IP Initiator Responder Application Connect to example.etri.re.kr Application Transport IP Initiator Connect to id: id: :110::1 2001:220::3 Packet to 2001:220::3 Fail Packet to 2001:110::1 Transport IP Responder ID-LOC separation 19

20 Candidate solutions Host based solutions Host Identity Protocol (HIP) IRTF and IETF RFC 4423 SHIM6 IETF RFC 5533 Network based solutions GSE/8+8 LISP ILNP IRTF draft draft-rja-ilnp-intro-03.txt Hybrid solutions Six/One 20

21 Solution space for Network based approach Separating Network domain Global Transit Network vs. Edge Network Global routable address vs. Global recognizable address Mapping database Global distribution Scalability Security Global Transit Network User Network or Edge Network 21

22 Locator ID separation protocol (LISP) A novel Internet routing and addressing architecture by Cisco Separate two different address spaces End Point Identifier (EID) Routing Locators (RLOC) Network (Router) based approach LISP clearly requires an out-of-band EID-to-RLOC mapping service A Map-n-Encap Scheme Procedures for tunneling by rewriting address where: 22

23 Two-level Addressing Provider A /8 Provider B /8 RLOCs used in the transit network Mapping Database Entry: R1 R /8 -> ( , ) S /8 EIDs are inside of sites 23

24 LISP Deployment Environment EID-RLOC Mapping system Proxy xtr Map-Resolver Map-Server 24

25 Consideration for LISP LISP Separation between RLOC and EID addresses solves the multihoming, traffic engineering Deployment Easy to enhance software at router Support Interworking Issues LISP clearly requires an out-of-band EID-to- RLOC mapping service While the baseline LISP infrastructure is quite stable, the mapping service is still somewhat hazy LISP-ALT is candidate 25

26 Issue: EID assignment Addressing can follow topology or topology can follow addressing choose one Y.R. Provider A /8 ISP allocates 1 locator address per physical attachment point (follows network topology) Provider B /8 R1 R2 RIR allocates EID-prefixes (follows org/geo hierarchy) Legend: EIDs -> Green Locators -> Red Site PI EID-prefix /16 LISP@ETRI 26

27 Identifier-Locator Network Protocol (ILNP) ILNPv6 provides full backwards compatibility with IPv6. provides full support for incremental deployment. IPv6 routers do not need to change. Integrated solution for Scalability, Mobility, and Multihoming ILNPv6 splits the IPv6 address in half: Locator (L): 64-bit name for the subnetwork Identifier (I): 64-bit name for the host Same architecture can work for IPv4 (ILNPv4), but a shortage of bits makes the engineering ugly 27

28 Critical Changes Transport Layer Transport-layer pseudo-header only includes IDENTIFIER, never the LOCATOR. IMPLICATIONS: We can multi-home nodes/sites without impacting routing. Mobility just became a built-in/native capability. DNS enhancement New resource record NAME DNS Type Definition Identifier I Names a Node Locator L Names a subnetwork Locator Pointer LP Forward pointer from FQDN to an L Record 28

29 Comparison LISP Logically split namespace into EID and RLOC Changes Only Edge router (xtr) ILNP Split IPv6 address in half Changes Protocol Layer ILNP LISP Application FQDN FQDN, IP address Transport Identifier IP address Network Locator, Identifier IP address MAC MAC address MAC address 29

30 Naming and addressing for DTN and CCN

31 Introduction to DTN Challenged Networks Characteristics Path & Link High latency & low data rate, disconnection, long queuing times Network Architecture Interoperability considerations, security End System Limited longevity, low duty cycle operation, limited resources Examples Terrestrial Mobile Networks, Exotic Media Networks, Military Ad-hoc Networks, Sensor and Sensor/Actuator Networks Evolution of DTN From IPN (Interplanetary Internet) To a broader class of heterogeneous networks DTN uses naming, layering, encapsulation, and persistent storage to interconnect heterogeneous portions of a larger network, irrespective of formal layer DTN Can use a multitude of different delivery protocols including TCP/IP, raw Ethernet, serial lines, or hand-carried storage drives for delivery 31

32 Introduction to DTN Delay/Disruption Tolerant Networking (DTN) Interplanetary Internet Deep space communication in high-delay environments To various operational environments Subject to disruption / disconnection / high-delay Delay Tolerant Networking Research Group (DTNRG) A research group chartered as part of IRTF (very active) Implementation DTN2 ION (Interplanetary Overlay Network) 32

33 DTN Architecture DTN architectural description Nodes and Endpoints A DTN node An engine for sending and receiving bundles DTN Endpoint A set of DTN nodes Minimum Reception Group (MRG) e.g., UNICAST/ANYCAST/MULTICAST/BROADCAST Endpoint Identifiers (EIDs) and Registrations Uniform Resource Identifier (URI) [RFC 3986] Express names or addresses for a wide range of purposes [URI scheme format] <scheme>:<scheme-specific-part> e.g., ether:// , dtn://*.nus.comp.nus.edu.sg Late Binding The binding of a bundle's destination to a particular set of destination identifiers or addresses does not necessarily happen at the bundle source cf) [Binding] Interpreting the SSP of an EID for the purpose of carrying an associated message towards a destination 33

34 Architectural Retrospective Naming, Addressing, and Binding dtn://*.columbia.edu.dtn ether:// fe or dtn: dona://a 1 =X 1 &a 2 =X 2 & &a k =X k 34

35 Content Networking The primary problem that the Internet was designed for has changed [Van] enabling end-to-end data conversations vs. enabling access to content people want named chunks of data rather than end-to-end conversations Content-Centric Network [Theo] Host-Centric User-Centric, Data-Centric, Service-Centric Rethink the Internet switch messages at the content level rather than the datagram level subsume search, caching, networked storage, and databases dissemination-oriented: focus on reaching information, not just nodes [Van] Van Jacobson, et al, Networking Named Content, ACM CoNEXT 2009 Rome, December, [Theo] Theodore et al, Towards a Content-Centric Internet, Synelixis, Thomson, Ericsson, CERTH/ITI, BT, Alcatel-Lucent

36 DONA Basic Design DONA (Data Oriented Network Architecture) Lookup-by-name Route-by-name Replacing DNS names with flat, self-certifying names Replacing DNS name resolution with a namebased anycast primitive (above the IP layer) Handled by Provided by Persistence Names Flat names Availability Name resolution Route-by-name paradigm, A name-based anycast primitive Authenticity Names Self-certifying names 36

37 Content-Centric Networking A packet address names content, not location Named data is a better abstraction for today s communication problems than named hosts Strategy layer Fine-grained, dynamic optimization Best exploit multiple connectivity under changing condition Security layer Secure content itself, avoiding host-based vulnerabilities 37

38 Name DONA Names are Self- Certifying and FLAT Naming organized around principals Each principal is associated with a public-private key pair Each data, service or any other named entity is associated with a principal Names are of the form P:L P is the cryptographic hash of the principal s public key L is a label chosen by the principal CCN Hierarchical, aggregatable names for locating and sharing data Partly meaningful to humans, reflect some organizational structure of their origin 38

39 Resolution DONA Achieve high availability By finding close-by copies and avoiding failures Resolution handlers (RHs) Performs name-based routing Each domain or administrative entity will have one logical RH New network primitives REGISTER(P:L) Set up the state necessary for RHs to route FINDs effectively FIND(P:L) A client issues a FIND(P:L) packet to locate the object named P:L CCN Name routing, already existing name routing table Update FIB and PIT (Pending Interest Table) Naming and FI 39

40 Content Networking Summary CCN is using named content as its central abstraction Rather than host identifiers CCN retains the simplicity and scalability of IP CCN offers much better security, delivery efficiency, and disruption tolerance CCN is designed to replace IP, but can be incrementally deployed as an overlay 40

41 Concluding Remarks Name, address Problems in Current Internet is closely connected to Internet principal Are All of you understood about these problems then, how to solve them Activities toward to Future Incrementally Internet is evolved as origin Internet history Make solution for urgent problems Ex, CIDR, IPvX, aggregated BGP, LISP, ILNP Fundamentally Internet would be revolved Design new architecture for name, address Ex, DTN, CCN, Current status ( 百家爭鳴 ) There are a lot of objects to be identified There are a lot of terms name, identifier, identity, address, locator, There are a lot of candidate solutions 41

42 Q & A 42