Carrier equipment and firmware provisioning engine
Telecoms infrastructure · Access network automation and kernel-level traffic control
A provisioning engine for a telecoms carrier that automates subscriber and access-network configuration across GPON terminals and core routers.
The challenge
The engine automates subscriber provisioning and access-network configuration across multi-vendor GPON ONT fleets (TR-069 / TR-181) and core network routers. Configuration trees reach several megabytes per terminal and must be parsed and mutated in constant O(1) memory without DOM allocation spikes.
Multi-step network changes must execute as a single atomic transaction across all target nodes—rolling back every device to its prior snapshot automatically if any rule is rejected mid-flight—while maintaining hardware NPU fast-path routing offload and sub-second multi-WAN failover.
- Config trees
- Multi-megabyte TR-069 and TR-181 XML parsed in constant O(1) memory
- Rollout
- Atomic multi-node transactions with automatic snapshot rollback
- Data plane
- Hardware NPU L3 fast-path offload and dynamic TCP SYN MSS clamping
- Failover
- Sub-second raw-socket BFD and ICMP probing across multi-WAN trunks
Architecture
Streaming configuration parser
Multi-megabyte GPON optical terminal configuration trees—spanning TR-069, TR-181, and vendor-specific schemas—are parsed and mutated by an in-house finite-state streaming lexer. By avoiding DOM tree construction in RAM, memory usage remains constant regardless of configuration file size.
Transactional multi-node rollout
An asynchronous provisioning coordinator stages multi-step configuration changes across access nodes and core routers. It captures a pre-change state snapshot on every device and automatically rolls the entire transaction back if any node rejects a rule mid-flight.
The provisioning coordinator drives a constant-memory streaming XML lexer and a binary router API client to stage atomic changes across the GPON ONT fleet and core routers with NPU fast-path offload, while a raw-socket prober monitors multi-WAN links to shift routing metrics and update local DNS zones automatically.
Hardware and protocols
Binary router control client
Persistent non-blocking sockets communicate directly with router control planes using length-prefixed binary word framing, parallel command tagging, asynchronous trap handling, and native encryption and compression stream codecs.
Hardware fast-path offload and MSS clamping
Interfacing with device forwarding planes and Linux kernel networking subsystems, the engine ensures layer-3 routing remains on the network processor (NPU) hardware fast path while dynamically clamping TCP segment sizes across PPPoE and VLAN trunks.
Sub-second link monitoring and failover
A background monitoring daemon transmits sub-second BFD and ICMP health probes over raw network sockets across multi-WAN gateways, shifting routing metrics and updating local DNS zone records atomically when packet loss crosses threshold.
Verification
The suite runs in isolated, unprivileged Linux network namespaces wired with virtual Ethernet pairs to mock appliance daemons that speak the binary protocols.
It covers recovery from malformed XML streams, length prefixes at every encoding boundary from one to five bytes, and sub-second failover convergence, and needs no physical routers or ONT hardware.