Dynamic Link Tagging for Multi-Domain Optical Network Call Setup
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Solution Overview
Problem
Current control plane systems in multi-domain transport networks, such as ENNI, face challenges with dynamic bandwidth updates and resource utilization, leading to high crank-back rates and inefficient call setups due to lack of bandwidth reservation and overbooking capabilities, resulting in suboptimal resource utilization and increased connection establishment times.
Innovation Solution
Implementing dynamic link tagging and overbooking mechanisms in multi-domain transport networks to reserve bandwidth and allow for overbooking of resources, enabling better resource utilization and reducing crank-backs by ensuring that resources are dynamically reserved and reused efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bandwidth advertisements are exchanged over dedicated channels in ENNI networks, then resource information is shared between domains, but the bandwidth information is not updated dynamically leading to high crank-back rates
Solution Approach 1:
The patent implements dynamic bandwidth advertisement updates by having border nodes continuously monitor and update available bandwidth information on ENNI links. Instead of static bandwidth advertisements, the system dynamically adjusts the advertised bandwidth based on current link utilization, allowing other domains to receive real-time updates about available capacity. This dynamic approach prevents calls from being set up on links that have become full, thereby reducing crank-backs while maintaining efficient call setup times.
2Ease of operation
If abstract links are used for inter-domain connections, then bandwidth allocation is simplified, but path validation is not comprehensive leading to call setups on invalid paths
Solution Approach 1:
The patent introduces a feedback mechanism where border nodes validate paths by checking current bandwidth availability before allowing call setups. The system continuously monitors link utilization and provides feedback information to routing decisions. This feedback loop ensures that abstract links are only used when they actually have available bandwidth, making path validation comprehensive without complicating the bandwidth allocation process.
3Productivity
If bandwidth is reserved for concurrent call setups, then resource utilization is optimized, but the ENNI link becomes a bottleneck rejecting new connections
Solution Approach 1:
The patent implements dynamic bandwidth advertisement that adjusts available capacity in real-time. When bandwidth is reserved for concurrent call setups, the system dynamically updates the advertised bandwidth to reflect the reduced available capacity. This allows the ENNI link to adapt to changing conditions, optimizing resource utilization while maintaining flexibility to accept new connections when bandwidth becomes available. The dynamic approach prevents the link from becoming a rigid bottleneck.
4Quantity of substance
If 32 simultaneous calls are supported on an OTU3 ENNI link, then bandwidth capacity is maximized, but the 33rd call is rejected even if resources are not yet involved
Solution Approach 1:
The patent implements a preliminary bandwidth reservation mechanism where the system anticipates potential call failures and reserves bandwidth in advance. When 32 calls are in progress on an OTU3 link, the system monitors the state of these calls and proactively reserves additional bandwidth for potential new calls. This preliminary action allows the 33rd call to be accepted even though resources are currently occupied, because the system has already prepared the necessary bandwidth allocation in case of call failures.
Data Source
AI summary
Call setup methods in a multi-domain network and a multi-domain network use dynamic link tagging and/or overbooking of External Network-Network Interface (ENNI) links. Thus, improved call setup systems and methods include two approaches to improve upon the responsiveness of the network for connection setups including bandwidth reservation in optical networks using “dynamic link tags” and link overbooking in optical networks based on a greedy approach. The bandwidth reservation and the link overbooking can be utilized together or separately to improve call setup. Advantageously, the improved call setup systems and methods can provide a generic bandwidth reservation mechanism, such as in Automatically Switched Optical Network (ASON) networks, to overcome the limitation of ENNI in concurrently updating the abstract link bandwidth and thereby improving the responsiveness of the network.