**3. Traffic engineering objectives**

Traffic Engineering (TE) is concerned with performance optimization of operational networks. More formally speaking, the key traffic engineering objectives are:


## **4. Components of traffic engineering**

One of the strategies for TE using MPLS involves four functional components [6]:


The Layer 2 network core design was used extensively when the service providers were introducing IP as an additional service into their WAN networks. Many large service providers have already dropped this approach because it does not result in the cost

Traffic Engineering (TE) is concerned with performance optimization of operational

1. **Minimizing congestion:** Congestion occurs either when network resources are insufficient or inadequate to accommodate offered load or if traffic streams are inefficiently mapped onto available resources; causing subsets of network resources to

2. **Reliable network operations:** Adequate capacity for service restoration must be available keeping in mind multiple failure scenarios, and at the same time, there must be mechanisms to efficiently and speedily reroute traffic through the redundant capacity. On recovering from the faults, re-optimization may be necessary to include

3. **Quality of Service requirements:** In a multi-class service environment, where traffic streams with different service requirements contend with each other, the role of traffic engineering becomes more decisive. In such scenarios, traffic engineering has to provision resources selectively for various classes of streams, judiciously sharing the

4. **Traffic oriented:** Traffic oriented performance objectives include the aspects that enhance the QoS of traffic streams. In a single class, best effort Internet service model, the key traffic oriented performance objectives include: minimization of packet loss, minimization of delay, maximization of throughput, and enforcement of service level agreements. Under a single class best effort Internet service model, minimization of packet loss is one of the most important traffic oriented performance objectives. Statistically bounded traffic oriented performance objectives (such as peak to peak packet delay variation, loss ratio, and maximum packet transfer delay) might become

5. **Resource oriented:** Resource oriented performance objectives include the aspects pertaining to the optimization of resource utilization. Efficient management of network resources is the vehicle for the attainment of resource oriented performance objectives. In particular, it is generally desirable to ensure that subsets of network resources do not become over utilized and congested while other subsets along alternate feasible paths remain underutilized. Bandwidth is a crucial resource in contemporary networks. Therefore, a central function of Traffic Engineering is to efficiently manage bandwidth

One of the strategies for TE using MPLS involves four functional components [6]:

network resources, giving preferential treatment to some service classes.

reduction or increase in switching speed that pure IP-based networks bring

networks. More formally speaking, the key traffic engineering objectives are:

become over-utilized while others remain underutilized [5].

useful in the forthcoming differentiated services Internet.

**3. Traffic engineering objectives** 

the restored capacity.

resources.

2. Path selection

1. Information distribution

**4. Components of traffic engineering** 


Now, discussing each of the components in detail:

