Artel's lessons learned Part 3: Networking and Transport
So far in this blog series, we’ve examined the importance of PTP-aware switches in an IP environment, as well as correct handling of Precision Time Protocol (PTP) data to ensure proper timing and synchronization. In this third post, we look at networking and transport — the actual movement of video, audio, data, control, monitoring, intercom, and other signals over the IP network.
Know Your Needs
Before you move your operations into the IP realm, it pays to take a close look at your requirements in terms of moving media and data over the network. How many sources will the network need to support, and what kind of media do you plan to move and in what format? Will media be compressed or uncompressed, and how will that affect your bandwidth requirements?
Will you be using the network to distribute intercom, monitoring, and control signals? What kinds of external sources or signals will you need to accommodate? What about general data on the network? The better you’re able to specify these details at the outset, the easier it will be for you to design or extend an IP network suited to your application and your operations.
Take a look at your existing facility and network too. What’s already installed in the way of IP transport? What about dark fiber? Do you have or need connections to any other facilities? Bring these factors into your network planning discussions as well.
Although your network requirements will undoubtedly evolve over time, careful planning on the front end can help you make a smooth launch and adapt more readily as your needs change.
Manage Setting to Optimize Transport
Your IP network will support more than just media, so it makes sense to organize and prioritize transport for different payloads. One way to organize various types of traffic is to establish and use VLANs to create a logical separation between them. When you apply the appropriate QoS settings on your PTP-aware switch, you can make sure that the most essential and time-sensitive flows are delivered with the highest priority.
As you know from prior blog posts, PTP data plays a critical role in enabling effective media-over-IP transport. In fact, as you configure your network, you’ll want to set PTP as the highest-priority flow. Media would come next, and then control, intercom, and monitoring. With the right settings, you can be sure that even when traffic ramps up, your most important flows are protected.
Configure and Test With Care
With IP-based transport, you gain a great deal of flexibility in connecting different devices and managing various flows. But with that flexibility comes greater opportunity for disconnects. The details matter, and there are more of them when you move from the simpler world of SDI to the more complex IP domain. Without an understanding of your requirements (and a plan to address those requirements), you may have problems right from the start, or you might see smaller issues pop up — and sometimes turn into big issues.
In addition to planning carefully, you might consider staging a similar network prior to deployment. This is fairly common for a greenfield site, with the network and new components tested at a remote site for interoperability and performance. For a facility update or upgrade, where you’re installing in place, you’ll likely want to undergo a gradual deployment process that allows you to configure and test prior to going live. The time and effort you dedicate to this process can save you time, money, and headaches down the road.