Frequently Asked Questions
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Knowledge Base > Accessories > I/O Expansion Cards
Which call managers will the Symetrix VoIP card work with?
The Symetrix VoIP card must be used with a SIP based proxy server.
Which PBX does the Symetrix VoIP card support?
Our products utilize SIP 2.0 to interconnect with VoIP servers. We found that while SIP is a standard, there are many variances in the way it is applied by VoIP providers. SIP 2.0 is a loose specification that allows the developers of SIP-based systems to make many decisions on features and functions. The consequence of this is that two SIP based systems can be completely SIP 2.0 compliant and completely incompatible.
We have gone to great lengths to optimize our solutions for market-leading providers. Symetrix’s VoIP Interface Card has been tested for interoperability with Cisco, Avaya, 3CX and Asterisk and we intend to continue to test interoperability with other systems.
Much of the setup and configuration of a VoIP system is out of Symetrix’s and the AV integrator’s control. This includes the configuration and components of the VoIP network. We will make every effort to support the configuration of our VoIP Interface Card but if there are issues with the VoIP Interface Card not functioning with systems for which we have not created a configuration tech note, we can provide guidance but troubleshooting will need to be done with the assistance of the enterprise IT department or telephony system provider and interoperability cannot be guaranteed. We are unable to assist with the configuration of VoIP PBX systems.
How many calls can be handled by a single VoIP card?
The Symetrix VoIP card has 2 lines per card. 4 call appearances per VoIP card (4 remote calls, 2 call appearances per line).
Which Codecs are supported by the Symetrix VoIP card?
G.722, G.711 (A-law and μ-Law), G.729 (including Annex B) and G.723.1. Note that G.729 Annex B is currently supported for received audio only, the full implementation of VAD for all codecs will be in a future release.
How can I determine the priority of the Codecs?
This is user configurable in the VoIP card’s web-based administration interface using a simple drag and drop method.
How many VoIP cards can be used in a Symetrix system?
Limited only by the hosting DSP hardware type and numbers used. A single Edge Frame can host up to 4 cards, while Radius AEC and Radius 12xEX can each host a single card.
Do I need a PoE switch for the Symetrix VoIP card?
No, the Symetrix VoIP card doesn’t require a PoE switch as it is powered from the DSP unit it is installed into. If a PoE switch is used, it will not damage the Symetrix VoIP card.
How do you define the extension number or subscriber number?
First the IT department needs to establish the extension number. Then it is entered in the VoIP card’s web-based administration interface.
Will the VoIP card work with DHCP and can it be assigned a static IP?
Yes, the VoIP card is set to DHCP by default. It can easily be assigned to a static IP if needed from Composer software.
Does the VoIP card support IPv6?
No, only IPv4 is supported at this time.
Can the VoIP card be set to auto-answer?
Yes. In addition a setting of 1-8 rings before auto-answer can be selected.
Where can you see the MAC address?
The MAC address can be found in Composer software and on the Web admin.
Is it correct to say the Symetrix VoIP card acts as an end-point?
Yes, the Symetrix VoIP card works the same as any other VoIP phone on the network.
Is each line considered a separate instance with its own IP and extension?
The Symetrix VoIP card has 2 lines, with 2 call appearances per line. Each line gets its own extension. Only 1 IP address is assigned per card.
Can each line be set to use different Codecs?
The Codec settings are assigned for each card, so the same settings apply to both lines on a card.
Can the lines be assigned different Qos (Quality of Service) levels?
The same settings apply to both lines per card. 802.1Q User Priority can be set from 0-7, as well as DSCP settings for Audio RTP and Call Control.
Can different VLANS be used on each line?
VLANS can be used but only one VLAN can be used per card, which applies to both lines because there is only 1 IP per card.
How do you dial out from the Symetrix VoIP card?
Dialing can be done from Composer software, as well as many other methods. Third party devices such as AMX or Crestron can be used for dialing via Ethernet (UDP and TCP-IP) or RS-232. SymVue software can also be used for dialing.
Can the 2 lines on a VoIP card be bridged together for a conference? Can lines from multiple cards be bridged together for a conference?
Yes, all lines connected to the system via multiple Symetrix VoIP cards can be combined. Each line must first be registered, but the combining of the lines is done within Composer software with mixing and routing.
Will the CISCO settings cause any confusion with the VoIP cards?
CISCO or other third party device manufacturers have no control of the Symetrix VoIP cards. Therefore the settings will have no bearing on Symetrix VoIP cards performance.
Troubleshooting VoIP issues by performing a data packet capture with Wireshark
Are all inputs on the 4 Channel Analog Input Card mic or line switchable?
Yes, all analog inputs are mic or line switchable.
SPDIF and AES are two channel formats, so does each of the two outputs on the 4 Channel Digital Output Card have more than one channel?
Yes, each channel on the card sends two channels of audio. They are labeled 1 / 2 and 3 / 4.
Does the 4 Channel Digital Input Card have sample rate conversion?
Yes, it will accept any rate from 12 kHz to 96 khz and covert it to 48 khz.
What is the max output of the 4 Channel Analog Output Card?
The max output is 24dBu.
Will the 2 Line Analog Telephone Interface Card work with a VOIP telephone system?
No, the 2 Line Analog Telephone Interface card works only with a POTS line.
Does the 4 Channel Digital Input Card have an impedance matching transformer?
Yes, it matches 110 Ohm for AES and 75 Ohm for SPDIF respectively.
Where can I find a conferencing application paper on the advantages of SymNet v. Biamp?
Is the SymNet AEC card compatible with the Radius 12x8?
No, only a DSP with a card slot will support the 4 Channel AEC Card, such as Edge and Radius AEC.
Will phantom power damage my non-condenser microphones?
Generally no, some older ribbon microphones are somewhat susceptible, but it’s always a safe bet to disable phantom power when not needed.
Why does the 4 Channel Digital Output Card have a word clock input when this is an output card?
It seems confusing at first glance, but the word clock output is there so that the 4 Channel Digital Output Card can output AES or spdif to a downstream device at any sample rate between 12 kHz and 96 kHz. When no word clock is connected the 4 Channel Digital Output Card will output at 48 kHz.
The 4 Channel Digital Output Card supports AES and SPDIF, how does it handle the different impedance of the two formats?
There is an impedance matching transformer on the 4 Channel Digital Output Card to switch between 110 Ohm and 75 Ohm.
Tips and Tricks for Successful AEC
Why are there word clock inputs on the 4 Channel Digital Output card?
SymNet digital outputs will be used to send digital audio to a 3rd party digital device which may be running on a different sample rate than Edge or Radius AEC’s internal rate of 48 kHz. With a word clock input respectively, each digital out pair can send audio at any sample rate between 32 kHz and 192 kHz.
What are some tips for dialing the SymNet 2 Line Analog Telephone Interface with a 3rd Party Control System?
Does the 4 Channel Analog Input Card have 48v phantom power on the inputs?
Yes.
Is it OK to hot swap a 4 Channel Analog Output Card with a different SymNet I/O card?
No, it is never OK to hot swap a I/O card in a SymNet DSP. Please take the Composer certification for more info on this procedure.
Does the 4 Channel Analog Input Card have the same mic pre as the Radius 12x8 and Radius AEC?
Yes, the same input circuit is used for all SymNet Composer hardware.
Where can I find AutoCAD files for EDGE and the Symetrix audio I/O cards?
The 4 Channel Digital Input Card support AES and SPDIF. How does it handle the different impedance of the two formats?
There is an impedance matching transformer on the 4 Channel Digital Input Card to switch between 110Ohm and 75Ohm.
Will the 2 Line Analog Telephone Interface Card send the caller I.D. info to a 3rd party control system?
Yes, see the SSYSS and GSYSS commands in the SymNet Composer External Control Protocol.
Does the 4 Channel Analog Output Card have any level controls?
Yes, the 4 Channel Analog Output Card has a gain fader with a range from Off to +12dB.
2 Line Analog Telephone Interface Card Creates New Possibilities with SymNet
If an AEC source is routed through the SymNet 4 Channel AEC Card module’s Aux In, can the analog input still be used?
Yes, the AEC source will come out of the AEC# output on the AEC Ins module minus any echo. The analog input will come out of the Direct# output of the AEC Ins module.
Why is there no word clock input on the 4 Channel Digital Input Card?
Word clock is embedded into both AES/EBU spdif, so no word clock input is needed.
Are Crestron and/or AMX External Control Modules available for the Analog Telephone Interface Card?
Does the SymNet Analog Input Card have full 48 v phantom power on all inputs?
Yes, all SymNet card inputs (analog or AEC) have full 48 v phantom power.
Can the 2 Line Analog Telephone Interface Card auto pickup phone calls?
Auto answer has three settings: Off, 2 Rings, and 4 Rings.
Does the SymNet 4 Channel AEC Card contain a processor?
Yes, there is a 400Mhz SHARC processor on the AEC card itself. This means there are no DSP resources used in Composer when utilizing AEC.
What if I order an Edge or Radius AEC Frame but do not fill up the card slots?
Filler panels will reside in the empty slots.
What is Phantom Power?
Phantom power derives its name from its invisibility to audio signals, even though the microphone cable carries both phantom power (as direct current) and audio signals (as alternating current). Specifically, the term phantom power means a positive DC voltage sent to the microphone on both audio leads, through current-limiting resistors which also serve to isolate the audio leads from one another. The front panel phantom power button applies phantom power via pins 2 and 3 of the mic input XLR connectors.
Do the inputs of the 4 Channel Analog Input Card need to be padded to receive the output of a mixer or console?
No.
Crestron Symetrix Dialer Example
Where can I find an Ethernet application with IP capable Symetrix products?
SymNet Remote Terminal is a UDP terminal test application for testing Ethernet-based control for Symetrix products.
Why is there no word clock input on the SymNet 4 Channel Digital Input Card?
In both AES/EBU and SPDIF the word clock is embedded into the digital audio, so the digital input card will synch to the sample rate of the incoming signal.
