Transcript PowerPoint Presentation - GROBJ The Problems We Have

GROBJ BoF:
Problem Statement
Dan Wing, [email protected]
v0.3, revised: 2-Nov-2009
GROBJ Problem Statement – GROBJ BoF – IETF76
1
Application Connection Problem
•
Things are getting more complicated
1.
2.
3.
4.
5.
IPv6/IPv4
Transport protocol
Path selection
Optimal path selection
NATs
GROBJ Problem Statement – GROBJ BoF – IETF76
2
Three Party Case
•
•
•
•
“Alice”, “Bob”, “Carol”
Slightly more complex
GRO’s model ◄
Solving this case
solves the 2 party
case
XMPP
XMPP
GRO
1
GRO
2
3
XMPP
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
carol
3
Two Party Case
• “Alice, Bob”
• Simple to understand
• demonstrates we
have a problem
XMPP
XMPP
voice, gaming
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
4
Setup: Alice and Bob
• Alice and Bob want to
communicate directly
XMPP
XMPP
– Interactive video
– File sharing
– Gaming
• They are using a
rendezvous service
(XMPP)
voice, gaming
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
5
Problem 1: IP Family
• Alice’s network
supports IPv6
XMPP
XMPP
• Bob’s network
supports IPv4
IPv4? IPv6?
• That’s a problem!
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
6
Problem 2: transport protocol
• Alice’s wants to use
fancy new transport
(e.g., MP-TCP,
SCTP)
XMPP
XMPP
• Bob’s network only
handles TCP
MP-TCP? SCTP?
• That’s a problem!
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
7
Problem 3: path selection
• Alice and Bob are on
several networks
XMPP
XMPP
• Which paths work?
?
?
• That’s a problem!
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
8
Problem 4: optimal path selection
• Alice and Bob are on
several networks
XMPP
XMPP
• Which paths work
best?
?
– cost
– performance
?
• That’s a problem!
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
9
Problem 5: NATs
• Alice is behind a NAT
– NAT64 or NAT44
XMPP
• Alice doesn’t have
global IPv4 address
scope.
XMPP
?
XMPP
• That’s a problem!
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
10
Problem Summary
• Solving the problems is hard.
• Most applications don’t bother
– “My users aren’t multihomed” – but WiFi,
wired Ethernet, and 3G/4G changes that
– “My application will use UPnP IGD”
– IPv6 transition: native IPv6, NAT64, NAT44
(DS-Lite)
• All applications should make the same
decisions
– Games, SIP, XMPP
GROBJ Problem Statement – GROBJ BoF – IETF76
11
Proposed Solution
• Applications send a
Generic Referral
Object (GRO)
– Contains everything
necessary to
communicate directly
XMPP
XMPP
GRO
1
GRO
2
3
XMPP
alice
GROBJ Problem Statement – GROBJ BoF – IETF76
bob
carol
12
GRO and ICE
• ICE also allows choosing UDP/TCP/IPv6/IPv4
• But, ICE is specific to SDP and SIP’s
Offer/Answer model
• ICE has been used by other protocols:
– RTSPv2, XMPP
• GROBJ is more general
– remove the intertwining of an application
– So that GROBJ can be useful to other applications
ICE: draft-ietf-mmusic-ice
RTSPv2 with ICE: draft-ietf-mmusic-rtsp-nat
XMPP with ICE: http://xmpp.org/extensions/xep-0176.html
GROBJ Problem Statement – GROBJ BoF – IETF76
13
GROBJ Purpose
• Provide guidance to applications to better
use host network connectivity
Applications
Today
• share one IPv4
address, and
maybe a port
Tomorrow with GRO
• Share all available IPv4
& IPv6 addresses and
ports, and transport
protocols
• Indicate preferences
GROBJ Problem Statement – GROBJ BoF – IETF76
14