challenges of service provisioning in mpls openflow
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Challenges of Service Provisioning in MPLS OpenFlow
Dávid JOCHA, András KERN, Zoltán Lajos KIS, Attila TAKÁCS
Ericsson Research
Hungary
WTC 2012
SDN Workshop
SPARC Semi-Centralized Control for Carrier-Grade Aggregation
Video
WEB
MPLS CP
MPLS CP
OF Switch
OF Switch
OF Switch
OF Switch
OF Edge
OF Edge
IP/MPLS core OPENFLOW MPLS Aggregation
NNI OSPF, LDP
RSVP-TE, BGP
OF Switch
Core MPLS
Core MPLS
Core MPLS
Services Clients
Client
UNI
IGMP
Centralized control Intelligence
MPLS CP
Control Protocols
Client
Control Protocols
basic forwarding functions
Control Entity
Legacy Distributed control
• SPARC aims carrier grade split architectures
• With focus on operators’ networks
• OpenFlow as split architecture enabler
Split control (OpenFlow-MPLS) in acc/agg, interworking with legacy IP/MPLS core
Heterogeneous Services on top of a Homogenous Transport
• Vast number of services
– Different characteristics, service specific control
– Service mix can change frequently and rapidly
Video
WEB
MPLS CP
MPLS CP
OF Switch
OF Switch
OF Switch
OF Switch
OF Edge
OF Edge
IP/MPLS core OPENFLOW MPLS Aggregation
NNI OSPF, LDP
RSVP-TE, BGP
OF Switch
Core MPLS
Core MPLS
Core MPLS
Services Clients
Client
UNI
IGMP
Centralized control Intelligence
MPLS CP
Control Protocols
Client
Control Protocols
basic forwarding functions
Control Entity
Legacy Distributed control
SPARC control framework
Transport
Controller
Aggregation Domain
Tunnel Management
End-to-End Tunnel Management NNI Protocols OSPF, LDP, RSVP-TE
OpenFlow controller kernel
Topology
DB Flow
management
vRIB
Interface
Mapper
Transport Visor Transport Visor Transport Visor Transport Resource Visor
Service
Controller
Service
Controller
Service
Controller
Generic controller
framework Adapted to our Use-case
Residential
Internet access
IPTV Business LAN
• Hierarchical controller structure – Layered control plane,
interworking with eachother
– Recursive Stacking
– Interfaces
Users
Users Channels
Multicast logic
Endpoints
DHCP OAM module
Control layer (n)
Control layer (n-1)
Control layer (n+1)
DP
CTRL
CTRL
DP
CTRL CTRL
DP DP
Service example 1: Virtual Private LAN Service (VPLS)
OF Switch
OF Switch
OF Switch
OF Edge
OF Switch
Client
Client OF1.0 MPLS or OF 1.1
OF Edge
Client
Transport Controller
VPLS Controller
Legend:
Service MPLS tunnel
Transport MPLS tunnel
Transport and service are the two mayor layers
Virtualized view of the
network
OF Switch
Service Example 2: Residential Service with BRAS
Video
WEB
OF Switch
OF Switch
OF Switch
OF Edge
OF Switch
Client
Client OF1.0 MPLS or OF 1.1
OF Edge
BRAS
MPLS OpenFlow Controller
NOX kernel
MPLS Transport Application
L2 VPN Control APP L3 VPN Control APP
Residential Service APP • Broadband Remote Access Server (BRAS) functions include:
– AAA
– PPP termination
Legend:
L3 MPLS VPN tunnel
aka IP-MPLS-MPLS
L2 VPN tunnel aka
ETH-PW-MPLS
Transport MPLS tunnel
L2 and L3 type tunnels contribute to the same (higher layer) service
What is missing in standard OpenFlow?
• Flexible encapsulation needed – L3 in L2: supported
– L2 in L3, L2 in L2: not supported
– L2/L3 connectivity on the top of MPLS Pseudowire (PWE)
• Stateful processing at endpoints – Per packet processing in controller does not scale
Data plane layers
OF MPLS
core MPLS OF
VLC server
OF MPLS
OF MPLS
OF Internal MPLS
End-to-End MPLS
PWE (E-TREE)
L2 connectivity
SE
OpenFlow protocol extension: Stateful processing and endpoints
• Packet processor
– Extending the datapath functionality with stateless
and stateful packet processing, backward compatible
– Examples: PW, LLDP, Meters, IPv4 defragmentation,
BFD, … Flow
Table
Flow
Flow
Flow
Flow
Port
Group
Processor
Processor
Processor
Flow
Table
Flow
Flow
Flow
Flow
Processor
Processor
Flow Processor
OpenFlow protocol extension: Pseudowires
• To be supported
– Bottom of stack bit support
(match, set)
– Push/Pop labels/GALS/G-
Ach header/control word
before Layer 2
– Ability to POP labels and
figure out data type
underneath it
– Ability to process control
word and G-Ach header for
OAM etc
Physical
Data-Link
PSN
PSN Convergence
PW Demultiplexer
Encapsulation
Payload
Sequencing
Timing
Payload Conv.
Outer MPLS Label
PW Label
Control Word Flags, Frag, Len, Seg#
RTP
Payload
Physical
Data-Link
PWE3 over
MPLS
Generic
PWE3
Example: PW Implementation (with BFD)
Flow
Table
Flow
Flow
Flow
Port
PW MPLS
Ingress
Flow
Port
BFD
User traffic
VCCV (IPv4 pkts)
PW MPLS
Egress
User traffic
VCCV (IPv4 pkts)
Flow
Flow
Table
Flow
Flow
Flow
Flow
Flow
Group
Port
Port
ETH
IP
TCP
IP
UDP
BFD
VCCV CV
ETH
MPLS (PW)
VCCV CV
ETH
MPLS (PW)
MPLS (LSP)
+metadata
VCCV CV
ETH
MPLS (PW)
MPLS (LSP)
VCCV CV
ETH
MPLS (PW)
+metadata
ETH
IP
TCP
ETH
IP
TCP
ETH
IP
TCP
ETH
IP
TCP
ETH
IP
TCP
ETH
IP
TCP
ETH
IP
TCP
IP
UDP
BFD
IP
UDP
BFD
IP
UDP
BFD
IP
UDP
BFD
IP
UDP
BFD
Outlook
• Management aspects
– OAM
– Network Management System
• QoS
– OpenFlow support
• Other encapsulation modes
– PBB
– GRE
top related