IP542N Wireless Deployment

Chapter 1 Before you start

Before you deploy your wireless router, ensure that it fulfills the following requirements:

Compatible chip solution

MTK chip, Ralink chip wireless router can be compatible with our IP542N. Of course you can also use other AP through the communication test experiment with our IP542N. We have found a manufacturer of AP can’t compatible our IP542N, which cause packet loss and jitter.

The wireless signal strength

The most appropriate phone signal strength should be in more than -60dbm. It must be above 70%.

Chart 1: Wireless telephone signal strength

Poor wireless signal can lead to a wireless link be unstabitily, affect the voice quality.

The number of access equipment limits

Each AP allows access within 20 wireless telephones.

Independent voice wireless router

We just only allow wireless telephone access to unit , it is forbidden to other wireless devices, such as mobile phone, laptop access our voice wireless router. You must install the independent wireless router for the equipments.

Wifi channel selection


Figure 2: wifi channel

Due to the adjacent channel will influence each other, so we need to choose a channel that the channel itself and the adjacent channel are more free , such as the channel 8 and channel 13 in the figure 2.

After the channel connected , the speed of pinging telephone address generally should be within 10 ms.


Figure 2

Wireless router parameters

Turn on  WMM of the wireless router and sets the bandwith to 20M。WMM can improve the priority of the voice communication , the bandwidth set to 20M can reduce the conflict between frequency band.
IP542N have set DSCP of voice to 63 already. Please set DSCP value of voice stream to 63 from IP-PBX also. Then WMM will transfer voice stream prior to data stream.

Figure 3

Chapter 2 Troubleshooting

Failure 1:  phone can't get IP address

Confirm your phone whether has wifi connected, you can found the menu on the LCD display whether ticking off the wireless SSID you connect. If not it shows a failure connection. And you can change the channel of your wireless router, see whether for channel selection result in failure connection with wireless router.

It still cannot get IP address if the wireless connection is successful, please check whether you have turned on the DHCP sever, and check whether the wireless router is assigned 192.168.1.X that this segment may conflict with phone LAN port address. Our IP542N has a default LAN address

Failure 2:  phone can't register

First you must determine whether the address of the server is accessible. You can try to access the Telnet of the phone, then from the command line ping the address of the registered sever. If you can access the server, check your account. The legitimacy of the account itself can adopt the way of softphone confirmation, such as eyebeam. If you still can not registered with a right account , please follow the figure to saving log and send to our manufacturer technical support to analysis.

Figure 4: syslog

Failure 3:  incoherent voice communication

In the case of incoherent call, you can try to direct dial the IP address of the other phone to determine the fault between wireless link and PBX.

You can also use the ping command to detect the response speed of the phone. The normal response speed should be less than 10ms. If the response speed is slowish, you need to check the wireless deployment issues in the first chapter