Residential VoIP Phone Service Providers
What function does the Linksys ATA provide?
The Linksys SPA2102 Analog Telephony Adapter (ATA) is a router that has been configured by the service provider to provide optimal Quality of Service (QoS) performance for VoIP applications, and network connectivity for computer equipment for SOHO and home network applications.
Although the SPA2102 is only configured with two physical data ports, (an external WAN port labeled "Internet" and an internal LAN port labeled "Ethernet," the router is capable of providing voice services for up to two phone lines* and data services for several network devices.* An additional VoIP account is required to provide access to the second phone port for a second phone line.
Where should I attach my Linksys ATA for best results?
The following four examples provide typical scenarios found in most SOHO or home network environments. Please read the scenario descriptions for the environment that most closely matches your needs, and connect the ATA to the internet hand-off from your Cable/DSL modem. For Ethernet or Fiber-to-Home network services, connect the ATA to the Ethernet hand-off as described in the following four diagrams.
Scenario 1 - This configuration is ideal for household networks with a single computer and a single phone line. The ATA “Internet” port should be connected to the Internet Service Provider's network hand-off and your home computer connected to the “Ethernet” port.
Figure 1. Simple network with one computer and one or more phones.
Scenario 2 - This configuration extends the network described in Scenario 1 with the addition of a small switch. By connecting the ATA’s “Ethernet” port to a small switch, you can extend the number of devices supported on your network.
Figure 2. Simple network with one or more computers connected via Ethernet, and one or more phones.
Scenario 3 - If you do not have a requirement for additional Ethernet LAN ports, but do require support for wireless devices, you may find it cheaper to purchase a Wireless Bridge. These units are essentially a Wi-Fi Access Point that does not provide any routing functionality and allows your existing network router to extend services through the Access Point via Wi-Fi connections.
By connecting the Access Point’s LAN connection to the ATA’s “Ethernet” port, wireless devices on your network will receive IP addresses and be able to connect to the internet while you are using your phone, and maintain call quality even during network downloads.
Figure 3. Small network with computers and other network devices connected via Wi-Fi, and one or more phones.
Scenario 4 - Many SOHO and small home networks need to support wireless network devices as well as Ethernet-connected devices. If you have a wireless Access Point on your network, Figure 3 shows how the Wi-Fi Access Point may be connected to your ATA. You may use your Wi-Fi Access Point behind an ATA even if it is a unified solution installed in a router with a built-in switch.
For optimal voice quality (this bears emphasis as voice quality can suffer if your network is improperly configured), your router should be connected to the “Ethernet” port of the ATA. If your router supports a “Bridge mode” option (known as Router mode for Linksys products), you should set the router to this mode and plug a connection from the router’s switch or LAN ports into your ATA. This mode will allow you to extend your network to support additional devices via both Ethernet and Wi-Fi.
Figure 4. Small network with computers and other network devices connected via Ethernet and Wi-Fi, and one or more phones.
Can I attach my Linksys ATA as a client on my network behind my router or firewall?
Yes, this will work, however, by doing so, you will not be able to take advantage of the Quality of Service (QoS) optimization that the units were designed to provide.
Since the ATA will have to compete for bandwidth with other devices on your network, the relatively small amount of bandwidth needed for a voice conversation may, at times, not be available especially during peer-to-peer file sharing sessions or when downloading large files from the internet.
Since the ATA is a router and can provide Network Address Translation (NAT) to allow you to support more than one computing device on your network, additional routers are not required. You may, however, need to add a small switch or wireless bridge to provide connectivity for other network devices such as additional computers, Wi-Fi-capable smart phones, and laptops that connect via Wi-Fi.
A table at the end of this page provides some suggested models that work for these applications. If you have an environment that requires a firewall or a more sophisticated routing device, please contact Titan Support and ask to have your ATA configured for Bridge Mode. Unfortunately, this mode will remove the QoS functionality, however, it will allow the unit to be placed on your network without providing routing and NAT services, and prevent conflicts that may arise by stacking multiple in-line routers on your network.
The ATA should still be placed as the first device connected to your internet connection as in Figure 3. This will have little or no performance degradation on your network as the unit is acting as a bridge or switch and will not have to perform routing, network address translation or QoS for voice services.