In the previous article we discussed why network reliability is crucial for UC solutions. This time I will explain why PoE switches are important to grant power continuity of the phone service to match those of traditional PSTN systems.
When switching from a legacy phone system to a modern UC server, many things are taken for granted by the buyer. For example, that the system will also work in case of emergency situations, like a power outage.
Home analog phones connected directly to a local exchange usually work in the case of power outages, as the local exchange uses a UPS system. Legacy PBXs worked in a similar way, either embedding a battery or relying on a separate UPS system.
Besides the platform, a key component to success is the quality of the network on which the platform will function.
In this blog article we will analyze which network devices must be chosen carefully, and which technologies we need to be familiar with to successfully deploy our UC solution.
Firewall / Routers
As seen in Reviewing Security Concerns of UC solutions, we should consider firewalls and routers only as support for enforcing security. The UC server and the connected devices must be secure, even in the absence of dedicated devices such as firewall / SBCs with packet inspection capabilities. This is achievable only by applying the best practises and security policies inside the UC solution.
SIP Trunking is the most popular way to add PSTN connectivity to a modern UC solution.
A few words of advice:
- Fax support: if the UC solution will need to transfer faxes, you need to make sure the operator has official T.38 capability.
- Routes quality: these should be extensively tested over national, mobile, and international destinations for the following:
- Audio quality
- Connection speed
- CID shown on the remote side
- Set custom outgoing CID: a great feature for mobility and call forwarding
The biggest factors to consider when choosing devices that will connect to your UC solution are: determining the required installation time and avoiding installation-related issues (lengthy installations, device-related errors, etc.).
FXS / ATAs
Ideally, all devices connected to a modern UC server should be IP endpoints (PCs or SIP Phones).
In practice, there are many reasons to stick to analog FXS ports to connect analog devices:
- Users do not need advanced features on their endpoints
- Most fax machines have no built-in VoIP capabilities and require an ATA
- Analog modems connections
- Substituting many twisted pair cables with CAT-5 or CAT-7 cables might be:
- Too expensive
- Not possible because the resulting Ethernet cable would be longer than the maximum allowed Ethernet length (100 meters)
In such cases, the easiest way is to connect an ATA, which is a converter between SIP VoIP and analog interfaces.
In the previous blog article (Insight into the user endpoint) I listed user endpoints. This time I am going to characterize what advanced services can be implemented via SIP phones.
On legacy systems and modern VoIP systems, feature keys can implement a large set of services:
- BLF (Busy Lamp Field), which displays the status of colleagues
- Parking slots
- Speed dial
- Send DTMF
- Trunk / line monitoring and use
Verify how many of these keys your users will need. Also, consider the possibility of providing such advanced services via the UC Client. For example, the user can own a basic VoIP phone for calls but manage all other operations (presence, monitoring, etc.) via the UC client on the PC.