The core function of a switch is to serve as a centralized appliance providing network access and connectivity to enterprise devices. Companies began upgrading their hubs to Ethernet switches starting some twenty years in order to improve network performance. This was achieved by the fact that rather than broadcast all data as hubs did, switches allow for port-to-port communication so that multiple devices can communicate with one another simultaneously. Switches back then were “rack it and forget it” like devices that once powered on, pretty much ran configuration free. All of that has changed today as enterprises can have thousands of devices within a single LAN, running multiple types of traffic running at different priority levels.
Isolating and Prioritizing Traffic through VLANs
Not all network traffic is the same. Some traffic is latency tolerant while others are not. For instance, imagine the CEO of the company initiating an important conference call at the same time a bookkeeper starts a print job involving more than a thousand pages. Both of these data streams would compete with each other, creating disruptions within the streaming VoIP conversation. In order to avoid this predicament and ensure the continuous uninterrupted flow of voice streaming, VoIP traffic should be isolated. This is done by configuring VLANs, which are available on most enterprise ready switches.
VLANs are created on all involved switches and then assigned to designated ports through the process of tagging and untagging ports. A port can be either an access port or a trunk port. An access port accommodates a single device such as a computer, printer, VoIP phone or wireless access point. A device becomes a member of a VLAN by simply plugging into its assigned port. Trunk ports are the ports that connect to other network infrastructure devices such as switches and routers. They are the pipelines that carry multiple VLAN traffic and distribute it to other parts of the enterprise. Devices only communicate within their own VLANs.
At the very least, most companies require multiple VLANs in order to accommodate their VoIP systems. Another popular use is to separate wireless traffic from traditional desktop traffic or further separate the management chatter of wireless AP’s that communicate with each other or a centralized management appliance. Many SMB enterprises can easily have a half dozen or more VLANs configured for their enterprises.
Multiple Topology Switch Types
Large enterprises today are not a flat plane network but are made up of multiple distributive layers connecting multiple sites, each site made up of multiple closets (MDFs and IDFS) that are interlaced throughout in order to ensure proper attenuation rates. For instance, a large public high school may have six IDFs that then feed into an MD that hosts the WAN connection. As a result, the enterprise requires multiple types of switches depending on the required functionality. For instance:
- Each closet contains access switches, which provide connectivity to traditional workstations and printers.
- Some closets will require PoE switches to provide power to devices such as wireless access points, digital cameras and VoIP phones.
- Each closet requires one switch to serve as its local core switch that connects to the core switch in the MDF through a trunk ports that can accommodate multiple types of media connectors (fiber or Ethernet). The MDF core switch then sends all outgoing traffic to the WAN connection or router. An MDF core switch must be robust and is often times a layer 3 switch that can perform basic routing as well.
- With all traffic being routed to it, the datacenter requires a high performance fault tolerant core switch to handle the insatiable workloads. While most switches throughout the enterprise will be fixed port switches, a datacenter core switch is usually of a modular design in order to maximize flexibility and future growth. A modular switch allows for hot swappable expansion modules to accommodate different types of ports, media types and even wireless managers and firewalls. These switches usually have dual power supplies too for redundancy.
The Need for 10 GB
The demand for increased bandwidth keeps continues to grow exponentially. It wasn’t long ago that 100 MB access ports were more than enough to accommodate the workloads of users. Access ports today are a gigabyte by default with trunk ports built for multigigabit bandwidth. What’s more, virtual host switches that accommodate a dozen or more virtual servers require 10 GB today ports today and it is becoming commonplace to find 10 GB core access switches for virtual environments in the modern day enterprise. In fact, the largest datacenters that host cloud infrastructures are even utilizing 40 GB switches today.
Don’t Go It Alone
Enterprises today require a switch expert to design optimal layer 2 infrastructures. Many businesses turn to managed service providers who have expertise in this field to design, implement and manage switch environments for their clients. If your business is located in the Houston area, turn to NSC where we have the experience and knowledgebase to ensure your switch infrastructure can deliver the performance your enterprise needs, now and the foreseeable future.