FTTH internal coding implementation
Coding guideline for FTTH + DSL + WiFi implementation in NMS Prime.
Parent hub: Application Internals
This is the hottest topic regarding our actual work. The space will change on a daily basis.
1.1. Overview
This page describes the recommended access-agnostic approach for speed provisioning and monitoring across GPON, Active Ethernet, DSL, and WiFi.
Related: Access-Agnostic PPPoE Provisioning · FreeRADIUS Integration · TR-069 and GenieACS Integration
1.2. The challenge
TR-69 is a provisioning protocol for CPEs only. This implies there is no standardised way of how to set modem speed rates (e.g. downstream/upstream 100 Mbit/s to 10 Mbit/s). Many operators address this by using a quick-and-dirty method of manually setting internet speeds at the OLT directly via CLI. The next logical step is easy but also dirty: using the CRM to somehow "connect via telnet or SSH and push the required speed rates via CLI (or better SNMP)". This will work but it comes at a high price.
Disadvantages of setting modem speed via CLI:
Every network architecture (GPON, Active Ethernet, DSL, WiFi) requires a different provisioning implementation
Vendor-specific CLI commands (or SNMP MIBs) make life hard for a generic implementation approach — switching OLT vendor will cause pain
ONU → OLT port mapping required; support team needs knowledge of FTTH connection circuits (ineffective/bad workflow)
Potential config race conditions / hazards — assume you are connected via SSH towards your OLT while the provisioning system also pushes config changes via telnet/SSH; this can lead to race conditions, especially while saving configs
1.3. Definitions
Protocol | Usage | Provisioning of |
|---|---|---|
TR-69 | Protocol for remote management of customer-premises equipment (CPEs) | CPEs only |
PPPoE | The Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol for encapsulating PPP frames inside Ethernet frames (Wikipedia) | Speed provisioning and monitoring for any device (DSL, GPON, AE, …) of used bandwidths |
1.4. Naming conventions
Shortcut | Meaning |
|---|---|
AE | Active Ethernet |
OLT | Optical Line Terminal |
ONU | Optical Network Unit |
DSLAM | DSL head end |
1.5. The solution
The solution is PPPoE with the following architecture:
OLT / AE / DSLAM serves all modems with a default profile of maximum speed, e.g. 1 Gbit/s down and upstream
A BRAS / BNG router with PPPoE is used for traffic shaping and bandwidth monitoring
Customer devices require PPPoE protocol for dial-in
Switches can be configured to only allow forwarding of PPPoE traffic
1.6. Dial-in workflow
PPPoE connection establishment
PPPoE server forwards user/password to RADIUS server
RADIUS server checks credentials and looks up RADIUS attributes of customer in database
Establish PPPoE tunnel
Steps 5 / 6 / 8 / 9 are accounting-related (optional for bandwidth monitoring).
