Transcript Issues in ATM Network Control - Washington University in

Wide Area OpenFlow
Demonstration
Jon Turner,
John DeHart, Fred Kuhns
Computer Science & Engineering
Washington University
www.arl.wustl.edu
SC
queue
CP
hdrFmt
net
FPGA
lookup
NOX
parse
Planned Wide-Area OpenFlow
NOX
Princeton
Stanford
WashU
to SPP
2
2
2
2
GaTech
3
3
Texas
3
OpenFlow Site
• Acts as gateway between Local OpenFlow
Network and SPP node with OpenFlow code
option.
• Implemented in NetFPGA?
• OpenFlow  SPP
• Receives Ethernet Frames from an
OpenFlow Switch
• Encapsulates Ethernet frames in IP/UDP
pkt
• Sends IP/UDP pkt to SPP
• SPP  OpenFlow
• Receives IP/UDP pkt from SPP node
• Removes IP/UDP encapsulation
• Sends Ethernet frame to OpenFlow
switch
NOX
Gateway
to SPP via I2
‹#›
SPP Node
NPE
TCAM
GPE
net
FPGA
queue
hdrFmt
CP
lookup
parse
SPP-NOX
Filter
Updates
OFP
SC
Switch
LC
‹#›
SPP Node
NPE
TCAM
GPE
net
FPGA
queue
hdrFmt
CP
lookup
parse
SPP-NOX
Filter
Updates
OFP
SC
Switch
NPE Lookup Key
LC
TRx IP DA Slice ID (VLAN)
0 Index
(11b)
(4b)
LC Lookup Key
Rsv Intf
(4b) (4b)
IP DAddr (32b)
Protocol
(8b)
UDP DPort (16b)
Rx UDP DPort (16b)
(1b)
MN Key Bits 111-80 (32b)
MN Key Bits 79-48 (32b)
Type
(8b)
MN Key Bits 47-16 (32b)
MN Key Bits 15-0 (16b)
‹#›
SPP Node
NPE
TCAM
GPE
net
FPGA
queue
hdrFmt
CP
lookup
parse
SPP-NOX
Filter
Updates
OFP
SC
Switch
LC

LC Lookup(Interface, IP DA, Protocol, Rx UDP Dport)  Slice ID
 Slice ID is encoded as VLAN used in Switch
 VLAN will be used as Slice ID in NPE on other side of Switch
‹#›
SPP Node
NPE
TCAM
GPE
net
FPGA
queue
hdrFmt
CP
lookup
parse
SPP-NOX
Filter
Updates
OFP
SC
Switch
LC


Rx Meta-Interface: (Interface, Slice ID, Rx UDP Dport)
NPE Lookup(Rx Meta-Interface, MN Key(112b))  Tx Meta-Interface
 Hit: Causes pkt to be sent out on specificed physical interface with a new encapsulation
header
 Miss: Causes pkt to be sent to SC for communication to SPP-NOX
‹#›
NPE Lookup Key



NPE Lookup Key:
 144 bits
 32 bits of Substrate Key
 112 bits of MetaNet Specific key
MetaNet Specific Lookup Key:
 112 bits
 For IPv4 MN:
 IP DA (32b)
 IP SA (32b)
 Src Port (16b)
 Dst Port (16b)
 Proto/TCP Flags (16b)
 Proposed For OpenFlow (109b)
 VLAN Valid (1b)
 VLAN (12b)
 Src MAC (32b): Low 32 bits of Source MAC
 Dst MAC (48b)
 Ethertype (16b)
We are considering increasing the size of the NPE lookup key to a total of 288 bits, giving us 256 bits for the MetaNet
specific lookup key.
 Thus allowing us to support the full OpenFlow key (232b)
‹#›
OpenFlow Required Actions


Forward:
 Forwarding the pkt to physical ports and the following virtual ones:
 All: Send pkt out all interfaces, not including incoming interface
 Controller: Encapsulate and send packet to the controller
 Local: Send the packet to the switch’s local networking stack
 Table: Perform the actions in the flow table. Only for packet-out messages
 Packet-out messages are data packets that the controller wants to have the
switch send out.
 In-Port: Send pkt out the input port
Drop
‹#›
SPP-OpenFlow Supported Req’d Actions


Forward:
 Forwarding the pkt to a physical ports and the following virtual ones:
 All: Send pkt out all interfaces, not including incoming interface
 Controller: Encapsulate and send packet to the controller
 Local: Send the packet to the switch’s local networking stack
 ???Table: Perform the actions in the flow table. Only for packet-out
messages
 Packet-out messages are data packets that the controller wants to have
the switch send out.
 In-Port: Send pkt out the input port
Drop
‹#›
OpenFlow Optional Actions


Forward
 Normal: process the packet using the traditional forwarding path supported by the
switch.
 Flood: Flood the packet along the minimum spanning tree
Modify-Field
 Set VLAN ID
 Set VLAN Priority
 Strip VLAN Header
 Modify Ethernet SMAC
 Modify Ethernet DMAC
 Modify IP SA
 Modify IP DA
 Modify Transport Sport
 Modify Transport DPort
‹#›
SPP-OpenFlow Supported Opt’l Actions


Forward
 Normal: process the packet using the traditional forwarding path supported by the
switch.
 Flood: Flood the packet along the minimum spanning tree
Modify-Field
 Set VLAN ID
 Set VLAN Priority
 Strip VLAN Header
 Modify Ethernet SMAC
 Modify Ethernet DMAC
 Modify IP SA
 Modify IP DA
 Modify Transport Sport
 Modify Transport DPort
‹#›
OpenFlow Switch/Controller Communication

Uses an SSL Connection
 Can we support this?
 If we use the NOX software, how easy is it to change this?
‹#›
OpenFlow Protocol (OFP)

Message Types:
 Immutable Messages:
 HELLO
 Exchanged between Switch and Controller upon connection startup.
 Negotiates OFP version to be used.
 ERROR
 Switch alerts Controller of problems or error conditions
 ECHO {REQUEST, REPLY}
 Initiated by either Switch or Controller, other side must reply.
 May be used to indicate: latency, bandwidth or liveness of the connection
 VENDOR
 Identifies Switch Vendor using IEEE OUI (Organizationally Unique Identifier)
‹#›
OpenFlow Protocol (OFP) (con’t)

Message Types:
 Switch Configuration Messages (initiated by controller)
 FEATURES {REQUEST, REPLY}
 Controller requests switch to report its capabilities
 GET_CONFIG {REQUEST, REPLY}
 Controller queries current configuration of switch
 SET_CONFIG
 Controller sets configuration parameters of switch
 No response
‹#›
OpenFlow Protocol (OFP) (con’t)

Message Types:
 Asynchronous Messages (Switch to Controller)
 PACKET_IN
 Packets with no matching flow entry are sent to controller
 Packets that match a flow entry with an action of “send to controller”
 FLOW_EXPIRED: switch reports expiration/removal of an entry.
 Flow entries have idle timeouts assigned for inactivity removal
 Flow entries have a hard timeout for removal regardless of activity.
 Timeout based removal is done by the switch and the controller is notified.
 PORT_STATUS
 Switch sends port status messages to report port configuration state
changes.
‹#›
OpenFlow Protocol (OFP) (con’t)

Message Types:
 Controller Command Messages
 PACKET_OUT
 Controller to send packets out a specified port on switch
 FLOW_MOD
 Add, Delete, Modify Flow entries in Flow Table
 PORT_MOD
 Set Switch port properties
 Statistics Messages:
 STATS {REQUEST, REPLY}
 Collect statistics from Switch
‹#›
OFP: FLOW_MOD Messages

ADD
Identical entry already exists (identical header fields and priority):
 Remove existing entry and its counters and add new entry.
 Conflicting entry already exists (same priority both could be match):
 Refuse addition and respond with OFPEFM_ADD_OVERLAP error message.
 No conflict:
 Add new entry so priority is handled appropriately.
MODIFY
 If a flow entry with identical header fields does not exist then the new flow entry
should be added and its counters zeroed.
 If one or more entries match then they are ALL modified
MODIFY_STRICT
 If all fields including wildcards and priority match then that entry is modified
DELETE
 If one or more entries match then they are ALL deleted
DELETE_STRICT
 If all fields including wildcards and priority match then that entry is deleted

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‹#›
SPP-OFP: FLOW_MOD Messages

ADD
Can we tell if there are conflicts?
MODIFY
 Only support _STRICT?
MODIFY_STRICT
DELETE
 Only support _STRICT?
DELETE_STRICT

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‹#›
OFP: Capabilities






FLOW_STATS
 Able to report per flow statistics
TABLE_STATS
 Able to report per Flow Table statistics
PORT_STATS
 Able to report per Port statistics
STP
 Able to support 802.1d spanning tree protocol
MULTI_PHY_TX
 Able to support transmitting received packet out multiple physical interfaces
IP_REASM
 Able to support reassembly of IP fragments
‹#›
SPP-OFP: Capabilities






FLOW_STATS
 Able to report per flow statistics
TABLE_STATS
 ???Able to report per Flow Table statistics
PORT_STATS
 Able to report per Port statistics
STP
 Able to support 802.1d spanning tree protocol
MULTI_PHY_TX
 Able to support transmitting received packet out multiple physical interfaces
IP_REASM
 Able to support reassembly of IP fragments
‹#›
Plan for SPP Implementation



Step 1: Fast Path Code Option Implementation
 Test using current set of control utilities to populate lookup table
Step 2: SC/NOX
 Implemented using out-of-band SSL connections
Step 3: SC/NOX
 Implemented through data path
 Still unclear how to support SSL for this.
‹#›