Transcript Inter-carrier Solution Enabled by the OIF NNI

Intra-Carrier Solutions
Enabled by the OIF NNI
Erning Ye
Nortel Networks
Reference Network
Metro
Metro
E-NNI
E-NNI
EMS
Regional
Regional
E-NNI
E-NNI
I-NNI
UNI
Core
Metro
UNI
E-NNI
E-NNI
Regional
EMS
Core
Metro
Multiple Control Domains
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Each domain could be a core, regional, or metro network.
The control inside each domain is independent:
• Different signaling control systems (e.g., proxy) with
different protocols (e.g., PNNI, CR-LDP, RSVP, etc.)
• Different routing control systems (e.g., centralized or
distributed) with different protocols (e.g., PNNI, OSPF, IS-IS,
etc.)
• Different protection and restoration mechanisms.
• Different EMS/NMS
• Use UNI or NMI to initialize and/or terminate connection
services.
• Different addressing scheme and/or space inside domain.
Implementation agreement on E-NNI between domains
provides end-to-end services that are transparent to users.
Sub-network Organization and Routing Areas
Sub-network
RA.2
RA.1
Sub-network
RA.2.2
Sub-network
RA.2.2.1
E-NNI
E-NNI
Sub-network
RA.2.1
Sub-network
RA.2.2.2
RA.top
RA.2.2.3
NNI Routing – Requirements
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Accept ITU-T G.7715 routing requirements,
architecture and terminology.
Scope of routing area is a consequence of subnetwork organization that is described in G.805 at a
given layer.
Subdivision of the network into routing areas where
the areas can contain smaller areas. This creates
routing levels.
4 levels of routing hierarchy is required by carriers
(OIF NNI requirement).
Interoperability between adjacent routing areas is
domain-domain routing protocol based on a
hierarchical link state protocol.
Sub-network Abstraction
and Routing Controller
Abstracted
intra-domain link
RA.2.2
RC
RC
RA.2.2.3
RC
RC
RA.2.2.1
RC
Abstract TE links
Centralized routing control
RA.2.2.2
Abstract node
Centralized routing control
Abstract TE links
Distributed routing control
NNI Routing
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Separation of transport plane and control plane:
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Separated address space for routing controller and
transport nodes
Separated topology for routing controller and
transport nodes
Routing control could be centralized or distributed.
Transport sub-network could be abstracted to be
one node or several border nodes with abstract
intra-domain links.
Transport routing’s main function is to provide path
computation to Connection Management (Control
plane). In hierarchical routing, the path is
computed at certain routing level.
NNI Signaling
Network Call Controller
Connection Controller
Domain A
Client
UNI
Domain C
Domain B
E-NNI
UNI
E-NNI
SPC Service
SC Service
Call
Segment
UNI
Segment
Sub-network
Segment
NNI
Segment
Sub-network
Segment
NNI
Segment
Sub-network
Segment
UNI
Segment
Client
Call/Connection
Separation and Call Segments
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Call model is part of ASON architecture (G.8080), G7713 and
OIF NNI.
In a multiple control domain environment, the end-to-end call
is achieved by concatenating multiple individual UNI, subnetwork and NNI call segments.
Each call segment could have multiple connections
associated with it (e.g., 1+1 path protection, virtual
concatenate connections).
Network call controllers and connection controllers are
defined in G.8080 and used in the NNI signaling specification.
• NNI call controller is responsible for associating the call
segments of NNI and sub-network
• NNI connection controller is responsible for signaling
protocol interoperability
NNI Application – Domain Based Recovery
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Call/connection separation and call segmentation by ENNI
enables domain based protection and restoration
ENNI can be used to separate rerouting (recovery) domain.
Each rerouting domain contains one or more than one call
segment (A rerouting domain may contain other rerouting
domains).
Each rerouting domain could have its own protection
mechanism, e.g., liner protection on ENNI link, APS protection
inside one domain, and 1+1 path protection in another
domain.
The call controller at ingress ENNI performs redial function in
the scope of rerouting domain.
The failure happens in one domain would not cause
connection teardown in other domains.
Recovery Example
X
Client
Client
E-NNI
E-NNI
X
Client
E-NNI
Client
E-NNI