Before applying cloud computing, therefore, it’s critical to examine the strength of the network to make certain that any weak points are located and eliminated. This assists to check that users receive the same QoS they are wont to when using local servers. Additionally, IT has to be made aware that traditional Ethernet network architectures may not be adequate in achieving the desired service levels. Here are 5 reasons why this is the case.

1. Classic Ethernet Networks are Hierarchical

Ethernet generally relies on a hierarchy of 3 or more tiers. Acting traffic between different server racks, for example, requires transitioning up and down this logical tree. The significant point here is that each step along the path adds to the full latency. To avoid bridge loops between different network segments, IEEE 802.1D Spanning Tree Protocol (STP) allows only one active path at a time between two switches. However, this leads to congestion on the Inter-Switch Link since the bandwidth is limited to that single link. There are, of course, variations of that STP protocol that seek to address this issue. Rapid Spanning Tree Protocol (RSTP) is a method defined in IEEE 802.1w that reduces the time it takes to respond to changes in network topology. Another approach is Multiple Spanning Tree Protocol (MSTP), IEEE 802.1s, which extends RSTP to include a separate spanning tree for each Virtual Local Area Network (VLAN) group and blocks all but one possible passage for that VLAN within the spanning tree.

2. Classic Ethernet Networks are Unintelligent

Classic alternates are configured to connect physical, not virtual, resources. Each port is separately designed with the QoS, security, VLAN traffic and other network policies required by that particular server. In a virtual world, however, VMs move from one box to another depending on traffic loads or maintenance requirements. Unless the port configuration follows the VM to its new physical location, the connection fails. What this means to IT is either manually reconfiguring the ports with each move, or implementing a more intelligent class of switches that have all the applicable policies available at all ports, and can utilize those policies that are applicable to the service that is connected at the time.

3. Classic Ethernet Networks Don’t Scale

Since Classic Ethernet networks are configured to allow only a single connection between switches, this limits the amount of traffic they can acquit.

The scalability of traditional Ethernet is problematic, particularly whenever an organization accepts, as it nearly always will, that cloud infrastructures will grow

To reduce the impact of this bottleneck, link aggregation groups (LAGs) permit multiple physical links to share the ISL. But this requires manually configuring all the ports in the LAG, a task that becomes increasingly complex as more switches are added.

4. Classic Ethernet Networks Are Inefficient

Referable the limitations of STP, only one link or LAG can be active at a time, lowering the utilization rate. Adding or removing a new link causes the entire network to pause while the network reconfigures a new loop-free tree. This process can take from a few seconds up to several minutes, disrupting traffic and sometimes causing server crashes.

5. Classic Ethernet Networks Are Complex

On classic Ethernet networks, each port on each switch needs to be configured with the applicable VLANs, QoS, security, network policies and protocols. As servers are added, more switches are needed and they can’t share a common configuration.