i-2 Internet problems

Taekyoung Kwontkkwon@snu.ac.kr

scalability• Network prefix keeps increasing

– Superlinearly• Forwarding info base (FIB) size in-

creases– routers in Default free zone (DFZ)

Why increase?

3Source: bgp.potaroo.net

• Multi-homing• Traffic engineering• Non-aggregatable prefix allocation

Multi-homing• reliability

company1

ISP1 ISP2

3.0.0.0/8 4.0.0.0/8

3.4.0.0/163.4.0.0/16

Traffic engineering (1/2)• E.g. load balancing

ISP2

ISP1

4.0.0.0/8

3.4.0.0/163.4.0.0/16

Traffic engineering (2/2)• E.g. load balancing

ISP2

ISP1

4.0.0.0/8

3.4.1.0/243.4.0.0/16

3.4.2.0/24

Why routing scalability mat-ters?

• FIB is expensive

ViAggre, “Making routers last longer with ViAggre”, NSDI ‘09

Virtual aggregation (ViAg-gre)

ViAggre: Basic Idea

ViAggre: Basic Idea

Data plane operations

Route stretch

Ingress -> aggregation point

Aggregation point -> egress

scalability• LISP (locator identifier separation

protocol)

mobility• Session continuity

– TCP/IP socket • IP address is fixed

– IP address is changed with mobility• Initial lookup

– DNS assumes static binding between domain name and IP address

– What if IP address of a host changes dy-namically?

mobility• Destination mobility

– Client changes her point of attachment during session

• Source mobility– What if source moves?

• What if both endpoints change their points of attachment simultaneously?

Taxonomy: mobility proposals

• L3– MIPv4, MIPv6, PMIP

• L4• Shim layer

IP mobility problem• Internet hosts/interfaces are identified by IP address

– Host identifier– Locator

• Moving to another network requires different network address– But this would change the host’s identity– How can we still reach that host?

Routing for mobile hosts

CH

MH

Home network

MH

CHMH = mobile host CH = correspondent host

Home network Foreign network

Foreign network

How to direct packets to moving hosts transparently?

5 slides are from Scott Midkiff @VT hereafter

Host-specific routes• There are numerous routers• There will be even more mobile hosts• Whenever a host changes its address, it

may have to be propagated across the In-ternet

?

LD (location directory) • identifier: location• home address (HoA): care-of address (CoA)

Mobile IP

Proxy Mobile IP

L4 Proposals• MSOCKs

– “MSOCKS: An Architecture for Transport Layer Mobility,” infocom ‘98

• SCTP– RFC 4960, “Stream Control Transmission

Protocol”• Migrate

– “An End-to-End Approach to Host Mobil-ity,” MobiCom ‘00

Migrate• Locate hosts through existing DNS

– Secure, dynamic DNS is currently deployed and widely available (RFC 2137)

– Maintains standard IP addressing model• IP address are topological addresses, not Ids• Fundamental to Internet scaling properties

• Ensure seamless connectivity through connection migration– Notify only the current set of correspondent

hosts– Follows from the end-to-end argument

Migrate Architecture

DNS Server

Mobile Hostfoo.bar.edu

Location Query(DNS Lookup)

Connection Initiation

Location Update(Dynamic DNS Update)

Connection Migration

xxx.xxx.xxx.xxxyyy.yyy.yyy.yyy

CorrespondentHost

Shim layer: Insert an ID-locator mapping layer

• Shim6– Level 3 Multihoming Shim Protocol for

IPv6 , RFC 5533• HIP

– Host Identity Protocol (HIP) Architecture, RFC 4423

Content delivery efficiency• P2P: BitTorrent• CDN• IP multicasting• Wireless multicasting/broadcasting• CCN

Content centric networking• FIB Scalability• Source mobility• Cache-BW tradeoff

Security: DDOS• DDoS

– Filtering-based– Capability-based

Security: PKI• PKI is vulnerable

– Certificate chain• certificate

Digital Certificate

“I officially approve the relation be-

tween the holder of this certificate (the user) and this par-ticular public key.

Source: Atul Kahate

Digital Certificate Signed by CA

Digital Certifi-cate

Subject Name: …Public Key: ……

CA’s Digital Signature

To verify this cer-tificate, we need to de-sign it using the CA’s public key. If

we can de-sign the certificate, we can safely assume that

the certificate is valid.

“de-sign” means to verify the message digest of certificate by using CA’s public key

CA Hierarchy

Root CA

Second Level CA

Second Level CA

Second Level CA

Third Level CA

Third Level CA

Third Level CA

Third Level CA

…

… …

PKI threats • Everybody can be a CA• A naïve/reckless/malicious CA may

issue a certificate to a malicious en-tity.

• The malicious entity runs a bogus server– Say, citibank.com

• Somehow DNS response of citibank.-com has the IP address of the mali-cious entity

• Then what?

Video adaptation• How to maximize users’ QoE in a cell

or a group of cells in adaptive multi-media framework

• QoS: throughput, delay, jitter, loss• QoE: PSNR, MOS, zapping time

Rate Adaptation is a must• Different devices• Link/path bandwidth• Dynamics

40/24

2Mb/s

1Mb/s 0.2Mb/s

0.5Mb/s

Online transrating/transcod-ing

• Original video is modified

41/24

Netmanias, 2012

Dynamic Adaptive Streaming over HTTP (DASH)

• Segments for multiple quality levels

42/24

Thomas Stockhammer, Qualcomm

Scalable video coding (SVC)• Multiple layers for progressive quality en-

hancement

Layered Encoder

Layer lLayer 3

Layer 1Layer 2

…

Layered Video

Base layer

Enhancement Layer

Spatio-Temporal-Quality Cube

* MDC: multiple description coding

Location-based Mobile Networking

• offloading• handoff• P2P communications

Data center networking• Monitoring• Re-routing• TCP

TCP for Big Data• “Understanding TCP Incast and Its

Implications for Big Data Workloads”• “Cascaded TCP: Big Throughput for

Big Data Applications in Distributed HPC”

Oracle Mapping System• Mobility• Routing scalability• Content delivery• Certificate Verification