NLSR

# Named-data Link State Routing(NLSR)

**Named-data Link State Routing (NLSR)** is routing for NDN under development.

NLSR's development is going on top of 

* [**ndn-cpp-dev**](https://github.com/named-data/ndn-cpp-dev)

* [**NFD**](http://redmine.named-data.net/projects/nfd/wiki)

* [**ChronoSync**](https://github.com/bruinfish/ChronoSync)

### UML of NLSR is available

* class diagram

* use case diagram

## NLSR's design

Conceptually NLSR is divided into four modules

1. Core

2. Communication

3. Routing

4. Security

### 1. Core Module

- Read and parse configuration file

- Stores all configurable parameter values

- Stores Adjacent in Adjacency list

- Stores advertising names in name prefix list

- Stores Link State Advertisement (LSA) in Link State Database (LSDB)

### 2. Communication Module 

- Handles synchronization logic of NLSR's LSDB updates

- Publish LSDB updates in router name

- Upon update notification send interest for LSAs

- Publish certificates updates

- Send interest to fetch certificates

- Processes all inbound/outbound interest/data of NLSR

### 3. Routing Module

- Calculate routing table ( depending configuration use link - state routing calculator or Hyperbolic routing calculator)

- Stores routing table 

- Creates and store Name prefix table ( Name prefix table entry is Name Prefix with nexthops list to reach that name)

### 4. Security Module ( This module will no longer be available later when NLSR will use NFD's rule based validator)

- Fetch, validate and stores certificate in Certificate Store

- If some certificate is fetched but waiting to be validated is recorded in waiting list

- After validation it is added in the certificate store otherwise discarded

- Validate each piece of data received by NLSR

- Sign data using router process keys before sending out