LEVER: Leveraging Routing Infrastruc-ture for Routing Scalability, Mobility

and Content NetworkingIEEE CCW, Oct. 2011

Ted “Taekyoung” KwonSeoul National University

Joint work with Ray at Rutgers, ES Cho at SNU, SC Kim at SNU

Routing scalability• Number of IP prefixes

Source: Geoff Huston@APNIC

Routing scalability• Multi-homing, TE, non-aggregatable

prefix assignment• Endpoint identifiers (EIDs) may have

to be separated from routing locators (RLOCs)

• Locator Identifier Separation Protocol (LISP) and so on

• Q1: How to find RLOCs from EIDs?

Mobility • Mobility becomes the norm

Data: ITU

Mobility • IP mobility–Many unsuccessful proposals

• Different contexts– Identifier and locator– Home address (HoA) and care-of-ad-

dress (CoA)– Initial address and new address(es)

• Q2: how to find CoA for HoA?

Content networking• Content-oriented Internet usage

Source: Limelight

Content networking• Two contrasting approaches– Route-by-name

• DONA, CCN,…• Scalability problem

– Lookup-by-name• P2P, CDN,…• Application-specific, cost

• The latter could be almost as efficient as the former

• Assume content ID is standardized, like URL• Q3: how to find the location for content ID?

A common mapping infra• FQDN IP : DNS• EID RLOC : routing scalability• HoA CoA : mobility• Content ID IP : content network-

ing

I. An Evolutionary Approach

FQDN IP• FQDN: www.cs.bu.edu Root

edu. com.

bu. mit.

(1)

(2)

(3)

(4)

Name

IP

Client

LocalMappingServer

cs.

EID RLOC• 58.10.46.147.in-addr.arpa

(EID: 147.46.10.58)Root

arpa. com.

in-addr. ip6.

147.

46.

(1)

(2)

(3)

(4)(5)

EIDClient

LocalMappingServer

RLOC

* Assume the ISP has class B address block: 147.46.0.0/16

HoA CoA• 58.10.46.147.in-addr.arpa

(HoA: 147.46.10.58)Root

arpa. com.

in-addr. ip6.

147.

46.

(1)

(2)

(3)

(4)(5)

HoAClient

LocalMappingServer

CoA

* Assume the ISP has class B address block: 147.46.0.0/16

Content ID (CID) IP• CID: www.cs.bu.edu/a.mpg Root

edu. com.

bu. mit.

cs.

www.

(1)

(2)

(3)

(4)(5)

CID

IP

Client

LocalMappingServer

* Assume, for each FQDN, a single server maintains mapping for all the URLs starting with the FQDN

Mobility in-depth

att.com

bu.edu

(1) HoA?

(2) HoA?

(5) CoA(4) HoA?

MobileNode

verizon.com(3) HMS

(6) CoA

Home Mapping Server (HMS)

Cor-res.Node

Correspon-dent/mobile NodeLocal/home Mapping Server

* Mobile node is a Verizon user, moves to BU* the HMS is the leaf in the DNS hierarchy

DNS

Mobility w/ caching

att.com

bu.edu

(1) HoA?

(2) To find cache

(6) CoA

(5) HoA?

(3) If cache miss

MobileNode

verizon.com(4)

HMS

(7) CoA

(8) CoA

HMS

Corres.Node

Hashed ID

Prefix

Local Mapping Server

00 A01 B10 C11 D

A B

C

D

DNS

* CN is a user of AT&T, which caches map-ping* Hashed value of MN’s HoA starts with 0b01

II. A Clean Slate Approach

1. So far, we talked about an evolu-tionary approach

2. There will be other mapping schemes, which should be supported in the Future Internet, e.g. RFID

3. DNS may be outdatedVerisign undertakes Project Apollo, which will grow capacity 1,000 times today’s level of 4 tril-lion queries to manage 4 quadrillion queries per day by 2020.

Building a mapping infra: a clean-slate approach

• Hierarchical vs. flat• Centralized vs. distributed

• Can we leverage the routing struc-ture to realize the mapping infra?

LEVER: Realizing mapping by lever-aging routing

• Mapping server co-locates with router– E.g. local mapping server = router

• For a given ID, how can we find a mapping server who is in charge?

LEVER: how to advertise IDs?• the ID space is divided among ASs

– Each AS is in charge of mapping for the IDs in its par-tition, which is advertised by BGP

– BGP router knows which ASs are in charge of which ID partition: AS mapping table

– We can extend/leverage BGP• A partition of an AS is divided among its routers

– Each router is in charge of mapping for the IDs in its sub-partition, which is advertized

– A router knows the IDs maintained by other routers in the same AS: router mapping table

– We can leverage intra-domain routing

AS 20: FP 001

AS 30: FP 010

(1)(2)

(4)

(5)

SolicitorRouter

BGP Speaker

FP ASN Locator0b000 8 10.10.10.10b001 20 100.100.20.1

0b010 30 100.200.30.1

… … …

SP Locator0b00 100.200.10.10b01 100.200.15.1

0b10 100.200.20.1

0b11 100.200.25.1

(3)

AccessRouter

AS Mapping Table

Router Mapping Ta-ble

100.200.20.1

100.200.30.1

* ID is 0b01010…

First prefix (FP)

second prefix (SP)

LEVER: how to find mapping of an ID

LEVER• Relies on IP routing• Overlay• Incentives– ICANN may enforce the mapping service• E.g. ID partition assigned address block

– ISP can offer registry operator biz

Thank you!

tkkwon@snu.ac.kr