Transcript Slides - TERENA Networking Conference 2002

The Future of Packet
Handling
Alan Taylor
The Future of Packet Handling
From Internet to Infrastructure
Maintain reliability and quality
Cap
Legacy
Data
Legacy
Data
Public IP
Grow
New Public
Internet
Network
Internet
Cable
Cap
Mobile
Voice
Voice
Grow IP to Multi-terabit
Agenda
 Packet
Handling Routing Nodes
 Packet
Handling across the Network
 Diffserv
 Packet
Traffic Engineering
Handling with Optical Paths
 GMPLS
Agenda
 Packet
Handling Routing Nodes
 Packet
Handling across the Network
 Diffserv
 Packet
Traffic Engineering
Handling with Optical Paths
 GMPLS
System Partitioning
Optimum System
Partitioning
Routing Software OS

Forwarding
Table
#1
Update
Packet
Processor
Forwarding
Table

#2
Switch Fabric
I/O Card
I/O Card



#3
Clean division of
tasks
Each partition is a
consistent interface
Light traffic levels
across partition
Independent scaling
design decisions
Each block works
well within its limits
Processes run in their own
protected memory space
 Modules can be restarted
independently and gracefully
SNMP
Security

Chassis Mgmt

Purpose built for Internet
scale
Optimised for stability as
never in forwarding path
Modular design for high
reliability
Adjacency Mgmt

Protocols
Routing Software OS


Best-in-class routing
protocol implementations
Operating System
Optimised Software Partitioning
Good data consistency

Real time functions poorly
served
Pre-Emptive Multi-tasking

Scheduled time slices to each
process

UNIX-like kernel operation

Separate real time functions

Not appropriate for shared data
functions
Security

SNMP
Process run until finished
Chassis Mgmt

Adjacency Mgmt

Co-Operative Multi-tasking
Protocols

Operating System
Agenda
 Packet
Handling Routing Nodes
 Packet
Handling across the Network
 Diffserv
 Packet
Traffic Engineering
Handling with Optical Paths
 GMPLS
What Is Traffic Engineering?
Source
Destination
Layer 3 Routing

Traffic Engineering
Ability to control traffic flows in the network

Optimize available resources

Move traffic from IGP path to less congested path
Traffic Engineering with MPLS
Egress
LSR
Ingress
LSR
User defined LSP
constraints
Common IP control plane
 Explicitly routed MPLS path
 Controlled from ingress using RSVP signalling
 Constraint Based Routing extensions to IS-IS or
OSPF
 Fast Reroute reliability options

Constraint-Based Routing: Service
Model
Operations Performed by the Ingress LSR
Extended IGP
Routing Table
Traffic Engineering
Database (TED)
Constrained
Shortest Path First
1) Store information from IGP flooding
2) Store traffic engineering information
Explicit Route
3) Examine user defined constraints
4) Calculate the physical path for the LSP
5) Represent path as an explicit route
6) Pass ERO to RSVP for signaling
RSVP Signaling
User
Constraints
Constraint-Based Routing Example
label-switched-path madrid_to_stockholm{
to Stockholm;
from Madrid;
admin-group {include red, green}
cspf}
Stockholm
London
Paris
Munich
Madrid
Geneva
Rome
Diffserv Aware Traffic Engineering
 Combines

Traffic Engineering with Diffserv
MPLS paths meeting per class service requirements
 Constraint
Based Routing per Class
 Bandwidth constraints per Class
 Admission Control per Class over different
bandwidth pools
 Independent Preemption Priority
 Specified in draft-lefaucheur-diff-te-proto-
01.txt
Constraint-Based Routing: Service
Model
Operations Performed by the Ingress LSR
Extended IGP
Routing Table
Traffic Engineering
Database (TED)
Constrained
Shortest Path First
1) Store information from IGP flooding
2) Store traffic engineering information
Explicit Route
3) Examine user defined constraints
4) Calculate the physical path for the LSP
5) Represent path as an explicit route
6) Pass ERO to RSVP for signaling
RSVP Signaling
User
Constraints
Constraint-Based Routing: Extended
IGP
Extended IGP
Routing Table



Traffic Engineering
Database (TED)
Distributes topology and traffic
engineering information
IGP Extensions

Maximum reservable bandwidth per CT

Remaining reservable bandwidth per CT

Link administrative groups (colour)
Mechanisms

Opaque LSAs for OSPF

New TLVs for IS-IS
Constrained Shortest
Path First (CSPF)
Explicit Route
RSVP Signaling
User
Constraints
Constraint-Based Routing: TED
Extended IGP
Routing Table


Traffic Engineering
Database (TED)
Maintains traffic engineering
information learned from the
extended IGP
Constrained Shortest
Path First (CSPF)
Explicit Route
Contents

Up-to-date network
topology information

Current reservable bandwidth of
links per CT

Link administrative groups (colours)
RSVP Signaling
User
Constraints
Constraint-Based Routing: User
Constraints
Extended IGP
Routing Table

Traffic Engineering
Database (TED)
User-defined constraints applied
to path selection







Bandwidth requirements per CT
Hop limitations
Administrative groups (colors)
Priority (setup and hold)
Explicit route (strict or loose)
Overbooking per CT
Preemption Priority for each class
Constrained Shortest
Path First (CSPF)
Explicit Route
RSVP Signaling
User
Constraints
Constraint-Based Routing: CSPF
Algorithm
Extended IGP
Routing Table
Traffic Engineering
Database (TED)
Constrained Shortest
Path First (CSPF)
For LSP = (highest priority) to (lowest priority)
Prune links with insufficient bandwidth for CT
Explicit Route
Prune links that do not contain an included color
Prune links that contain an excluded color
Calculate shortest path from ingress to egress
Select among equal-cost paths
Pass explicit route to RSVP
END FOR
RSVP Signaling
User
Constraints
Constraint-Based Routing: with DS-TE
Seattle
Chicago
New
York
San
Francisco
Kansas
City
Los
Angeles
label-switched-path SF_to_NY {
to New_York;
from San_Francisco;
CT EF
BW 100 MB;
}
Atlanta
Dallas
Agenda
 Packet
Handling Routing Nodes
 Packet
Handling across the Network
 Diffserv
 Packet
Traffic Engineering
Handling with Optical Paths
 GMPLS
The Emerging Two-Layer Network
IP Service
(Routers)
Optical Core
Optical Transport
(OXCs, WDMs)

Packet Routing Layer providesAny-to-any datagram connectivity
 Packet Processing granularity
 Class of Service classification and handling
 IP service delivery


Optical Layer provides flexible optical bandwidth

Dynamic provisioning of optical bandwidth provides
growth and innovative service creation
Generalized MPLS
 Extends
MPLS control plane to support
multiple switching types
 Packet
switching
 TDM switching (SONET/SDH)
 Wavelength switching (lambda)
 Physical port switching (fiber)
 GMPLS
sets up LSPs of a particular type
(therefore between like devices / ports)
 Eg, Router-to-Router using TDM or l-switch;
 Or, TDM-to-TDM using l-switch;
 Etc.
Generalized MPLS
 Uses
existing and evolving technologies
 Based
on IP routing and signaling
 Builds on MPLS, and includes MPLS
 Distinction: packet vs. non-packet MPLS
 Is
not a protocol, but a suite of protocols
 Just
as MPLS is not a protocol
 Facilitates
parallel evolution in the IP
and transmission domains
 “Supports” peer and overlay models
Overlay and Peer Models

Overlay model


Two independent control planes

IP/MPLS routing

Optical domain routing

Router is client of optical domain

Optical topology invisible to routers
Peer model

Single integrated control plane

Router and optical switches are
peers

Optical topology is visible to routers
?
GMPLS Mechanisms
Extensions to OSPF and IS-IS
 Forwarding adjacency
 LSP hierarchy
 Constraint-based routing
 Signaling extensions
 Link Management Protocol (LMP)
 Link bundling

GMPLS: IGP Extensions

ISIS extensions to carry GMPLS information

New sub-TLVs for Extended IS Reachability TLV
Outgoing/Incoming Interface Identifier
 Maximum LSP Bandwidth
 Link protection


New TLVs
Link descriptor (encoding and transmission rate)
 Shared risk link group (list of SRLGs)


Defined in draft-ietf-isis-gmpls-extensions-09.txt
GMPLS: IGP Extensions

OSPF extensions to carry GMPLS information

New sub-TLVs for the Link TLV within the TE Opaque LSA






Outgoing/Incoming Interface Identifier
Link protection type
Link descriptor (encoding and transmission rate)
Shared risk link group (list of SRLGs)
Maximum LSP bandwidth sub-TLV (replaces maximum link bandwidth)
Defined in draft-ietf-ccamp-ospf-gmpls-extensions-05.txt
GMPLS: Forwarding Adjacency
Ingress Node
(low order LSP)
Ingress Node
(high order LSP)
ATM
Switch

SONET/SDH
ADM
SONET/SDH
ADM
FA-LSP
Egress Node
(high order LSP)
Egress Node
(low order LSP)
ATM
Switch
A node can advertise an LSP into IGP
Establish LSP using RSVP/CR-LDP signaling
IGP floods FA-LSP
 Link state database and traffic engineering database maintains
conventional links & FA-LSPs




A second node wanting to create an LSP can use an FA-LSP
as a”link” in the path for a new lower order LSP
The second node uses RSVP to establish label bindings for
the lower order LSP
GMPLS: LSP Hierarchy
PSC
Cloud
TDM
Cloud
LSC
Cloud
FSC Cloud
Fiber 1
Fiber n
LSC
Cloud
TDM
Cloud
PSC
Cloud
Bundle
FA-PSC
FA-TDM
Explicit
Label LSPs
Time-slot
LSPs
FA-LSC
l LSPs
(multiplex low-order LSPs)




Fiber LSPs
l LSPs
Time-slot
Explicit
LSPs
Label LSPs
(demultiplex low-order LSPs)
Improves scalability through LSP aggregation
Packet capable links can support multiple levels
via label stacking
Allows hierarchy of link aggregation mechanisms
LSPs always start and terminate on similar
interface types

Achieved via construction of LSP regions
GMPLS: Constraint-Based Routing
Extended IGP
Routing Table


Traffic Engineering
Database (TED)
Reduce the level of
manual configuration
Input to CSPF:
Path performance constraints
 Resource availability
 Topology information
(including FA-LSPs)
Constrained Shortest
Path First (CSPF)
Explicit Route


Output: Explicit route
for GMPLS signaling
RSVP Signaling
User
Constraints
GMPLS: RSVP Signaling Extensions
PATH
SONET/SDH
ADM

RESV
SONET/SDH
ADM
Label Related Formats

Generalized Label Request
Link Protection Type
 LSP Encoding Type

Generalized Label Object supports implicit TDM, λ, or fiber
labels
 Suggested Label
 Label Set


Support for bidirectional LSPs
GMPLS: Link Management Protocol
LMP


Control channel management
Link property correlation
Additional tools specified for LMP



LMP
LMP
Core functions of the Link Management Protocol


LMP
Link connectivity verification
Fault isolation
See draft-ietf-ccamp-lmp-03.txt
Conclusion

Routing Nodes based on clean and consistent
partitioning


Handling different traffic classes across the
Network


Hardware and software
Diffserv Traffic Engineering
Routing Layer interaction with Optical Paths

GMPLS
Thank You
http://www.juniper.net