Alcatel-Lucent 7750 SR-OS, Configuration Manual

Page: 583 / 674

Hybrid
Open Flow Switching
7750 SR OS Router Configuration Guide Page 583
Hybrid OpenFlow Switch Traffic Steering Details
As described in the previous section, an update to an OpenFlow Switch’s flow table, results in the
embedded filter update(s), which triggers update to all filter policies embedding those filters. The
router automatically downloads the new set of rules to the line cards as defined through service
configuration. The rules became part of ingress line card pipeline as depicted by the below picture:
Figure 27: OpenFlow Switch Embedding in Ingress Pipeline Processing
Redirect to LSP
The router supports traffic steering to an LSP. The following details the OF encoding to be used by
an OF controller:
flow_mod: instruction=write_action, action=output_port, port=LOGICAL
,
where:
LOGICAL
port encodes an LSP follows:
0
100 0000 0000 0000 xxxx xxxx xxxx xxxx
, where the first octet indicates the router’s
logical port, the second octet indicates the platform’s tunnel (set to all 0’s), and the remaining two
octets encode LSP identifier:
TunnelID
for RSVP-TE (static or dynamic) or
Tunnel Number
for
MPLS-TP.
A received LSP in a flow rule is compared against those in the H-OFS logical port table, if the
table does not contain the LSP the rule programming fails. Otherwise, the rule is installed in an
ACL filter. As long as any path within the LSP is UP, the redirect rule will forward unicast IP(v6)
traffic on the currently used best LSP path by adding LSP transport label and, in case of IPv6
traffic, additionally adding explicit NULL label.
al_0369
Intf ACL
Rules
IP Filter Policy Table (IPv4 or IPv6)
Ingress Line Card Pipe-line Processing
QoS Table Tunnel/
Routing
Queuing
Policing
Interface
Table
Ingress
Port
Egress
Port
OF
Switch
Flow
Table
ACL
Rules
QoS
Policy
Rtg
Fwd
QoS/TM