global name resolution services through direct mapping...

Global Name Resolution Services Through Direct Mapping (DMAP)

Presented by: Yanyong ZhangWINLAB, Rutgers University

Technology Centre of NJ671 Route 1, North Brunswick,

NJ 08902, USAyyzhang@winlab.rutgers.edu

Name-Address Separation Through GNRS Globally unique name

(GUID) for network attached objects device, content, context, AS name,

and so on Multiple domain-specific naming

services

Global Name Resolution Service for GUID NA mappings

Where to store these mappings?

Globally Unique Flat Identifier (GUID)

John’s _laptop_1

Sue’s_mobile_2

Server_1234

Sensor@XYZ

Media File_ABC

Host NamingService

Network

SensorNamingService

ContentNamingService

Global Name Resolution Service

Network addressNet1.local_ID

Net2.local_ID

ContextNamingService

Taxis in NB

A distributed service hosted on ~10,000 gateway routers Fast updates ~50-100 ms to support dynamic mobility Service can scale to ~10B names

AP

Global Name-Address Resolution Service A

Data Plane

Host GUID

Network – NA2

Network – NA1

Network Address 1

Registrationupdate

Mobile nodetrajectory

Initialregistration

GUID Network Address

Host GUID

Network Address 2

GNRS Design Objective

(00101100……10011001)

Hash Function

GUID

IPx = (44.32.1.153)IP

(+) Strictly 1-overlay-hop lookup No extra routing requirement

(e.g. utilize current BGP)

(-) IP “hole” issues Limited locality

Direct Mapping (DMAP)

Fixing IP Holes: If hash of GUID falls in

the IP hole, rehash that IP m times to get out of the hole

Lookup follows the same process to find GUID

Value at m=10 is 0.0009

Map of IP (/8) address space (white = unassigned addresses)

Fixing IP Holes for IPv4

Fixing IP Holes for General Network Addressing Schemes In a general network addressing scheme, we can have more

holes than used segments (e.g., IPv6) Used address segments are hashed into N buckets

a two-level index: (bucket ID: segment ID)

Mapping GUID to NA H1(GUID) bucket ID H2(GUID) segment ID within a bucket

network address space

used segments

unused segments

(2, 1) (1, 1) (1, 2) (2, 2)

IPx = (44.32.1.153)

Every mapping is replicated at K random locations

Lookups can choose closest among K mappings. Much reduced lookup latencies

K=1

K=2

K=3

Mapping Replication

k Hash Functions

GUID

IPIP

(00101100……10011001)

IPx = (67.10.12.1)IP

IPx = (8.12.2.3)

Spatial locality: GUIDs will be more often accessed by local nodes (within the same AS)

Solution: Keep a local replica of the mapping A lookup can involve simultaneous local lookup and global lookup

GUID 10

GUID AS#10 1

K=1

AS 1

AS 5

GUID AS#10 1

K=2

AS 101

GUID AS#10 1

K=3AS 200

GUID AS#10 1

Local replica

Capturing Locality

GNRS

1. GUID Publishing2. GNRS

lookup3. GNRSReply: H

H’

H

C

Inconsistent GNRS Entries

GUID NAC H

GNRS

1. GUID Publishing2. GNRS

lookup3. GNRSReply: H

GUID NAC H

6. Keep checkingGNRS until H’

GUID Update

H’

H

Inconsistent GNRS Entries

GNRS

1. GUID Publishing2. GNRS

lookup3. GNRSReply: H

GUID NAC

6. Keep checkingGNRS until H’

GUID Update

H’

H’

H

Inconsistent GNRS Entries

Simulation Results – Query Latencies

Simulation Results – Load Distribution

Open Issues

GNRS performance with tomorrow’s Internet model Sophisticated locality considerations Caching GNRS mappings Security and privacy

Large scale prototyping and validation

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Questions & Answers