IP Profile

Use this pane to define a set of VoIP parameter values such as Silence Suppression, Echo Cancellation and RTP Redundancy.  After creating and configuring the IP Profiles object, assign it to a SIP channel group to define inbound or outbound behavior. To create the IP Profiles object, right-click on the Profiles object and select New IP Profile. After creating the IP Profile object, commit the profile by going back to the Profiles object pane and click the Download Tables button. After creating the profile, use the Supported Vocoders pane to assign a list of supported codecs to the profile.   

 

Note: The 2020 IMG has an adaptive Jitter Buffer which adjusts its size dynamically. The minimum is 75ms and the maximum is 150ms. The Jitter Buffer is not configurable.

 

ClientView Pane

IMG EMS > Profiles > IP Profiles.

SC_IP_Profile.png

 

Maximum Objects

Up to 16 IP profiles can be created per Profiles object.

 

Related Topics and Dependencies

After creating and configuring the IP Profiles object, assign it to a SIP channel group to define inbound or outbound behavior.

Profiles

SIP (SGP) Profile

 

Field Descriptions

IP Bearer Profile ID

The ID field configures an ID onto the IP Profile being created and is populated with the next available ID. The value can be changed by selecting a different ID from the drop down menu. Values range from ID:1 to ID:16 and once created cannot be reused or modified. The ID configured will subsequently be used in the Channel Group object to specify the IP Bearer Profile instance.

 

IP Bearer Profile Name

Click in the Name field and enter a name that identifies the IP Profile being created. A maximum of 19 characters is allowed. Click on the Valid Characters link. The link displays the valid characters that can be used in the naming process. The Name value provides a name to the profile being defined. The Name is subsequently used in the Channel Group object to specify the IP Bearer Profile instance.

 

 

Silence Suppression

During a normal voice conversation, much of the time is wasted on silence from one or both ends. Ethernet bandwidth can be conserved if during these periods of silence RTP packets are sent with silence-encoded compressed payloads. The 2020 IMG Silence Suppression feature supports the concepts of Voice Activity Detection (VAD) and Comfort Noise Generation (CNG). When enabled Silence suppression will not send RTP traffic during periods of silence, saving bandwidth usage. At the beginning of a silence period, a single packet will be sent to the distant end to inform it that a period of silence is being entered, and that the distant end should begin to regenerate comfort noise to its TDM stream. Silence Suppression can be enabled or disabled on an established connection. Silence Suppression does not apply to the AMR codec as it has its own internal Silence Suppression scheme.

Enable - Silence Suppression algorithm is enabled

Disable - Silence Suppression algorithm is disabled.

 

Note: For SIP calls silence suppression is enabled by default. In the default configuration the attribute is not sent unless it is specifically set to off. In the case of Fax re-invites if Silence Suppression is set to off the line a=silenceSupp:off - - - -  is included in the SIP SDP message.    

 

Echo Cancellation

In compliance with ITU G.168-2000, this feature eliminates echo introduced by impedance mismatched hybrids on TDM channels. The maximum tail length is 128 milliseconds for the VoIP Modules installed in the 2020 IMG. Echo Cancellation may be implemented for tandem calls on trunks with echo or to clean an incoming signal before connecting to a media resource, such as a Voice Response Unit or Answering Machine Detection. Echo cancellation is not supported in the AMR codec.

A Non-Linear Processor control support feature is included in the selections below. This subcomponent of Echo Cancellation can be enabled and disabled when Echo cancellation is set to enabled. See below.

Enabled (NLP Enabled) (Default) - Echo Cancellation is enabled along with the Non-Linear Processor sub-component. The Nonlinear Processor (NLP) is used to remove the residual echo signal, that is, the components that could not be removed by the linear filter alone. The NLP is not activated during periods of double talk.

Enabled (NLP Disabled) - Echo Cancellation is enabled but the Non Linear Processor sub-component is Disabled. Disabling the NLP while echo cancellation is enabled, is in cases where heavy double-talk scenarios are expected. Double-talk results in clipping (removal) too much voice from the voice path, causing the voice recognition software to fail to detect voice patterns. Disabling the NLP solves this problem.

Disable - Echo Cancellation is disabled

 

RTP Redundancy

RTP Redundancy provides RTP packet redundancy to guard against network packet loss (RFC 2198) for RTP traffic in voice or fax/modem bypass calls. RTP Redundancy is not supported in AMR. AMR has internal schemes that are not configurable. Note that Open Phone does not support RTP Redundancy. Selections shown below.

No Redundancy - RTP packet redundancy is disabled.

Redundancy Level 1 - RTP packet redundancy is enabled. When redundancy level 1 is selected, the RTP Payload Type Redundancy field below can now be modified and the packet payload type can be modified.

 

RTP Payload Type for Redundancy.

Note: This field can be modified when RTP Redundancy field above is set to Redundancy Level 1.

The numeric value displayed in drop down menu (96-127) defines the packet type being sent for RTP Redundancy. For an incoming call, if the sending gateway is using a codec that is configured on the 2020 IMG but is sent with a different dynamic payload type, the 2020 IMG will accommodate that by responding with the dynamic payload type sent by the sending gateway in the INVITE message.  For example, if the 2020 IMG has an AMR profile configured with a value of 100, an incoming call to the 2020 IMG has AMR set to 98, the 2020 IMG will send the 98 back in the 200 OK to accept the AMR Codec.

 

Fax Mode

Defines the mode of operation for Fax Calls.

Enable Relay (T.38) - The fax is delivered using T.38 packets.

Enable Bypass - The codec configured in the Fax Bypass Codec field below is used to send the fax. This functionality is not supported for the AMR and EVRC codecs.

Relay Fallback to Bypass -  The Fax Fallback feature is a backup mechanism to transmit a fax using Fax Bypass mode when T.38 cannot be negotiated successfully. This feature allows you to configure T.38 Fax Relay as the preferred type, and also allow Bypass Fax when T.38 is not supported by the remote end. The added negotiation will therefore reduce the call setup failure rate by increasing the content of the media offer. In the event neither a T.38 fax nor a Bypass fax can be established in a fax fallback scenario, the 2020 IMG allows the voice call to proceed as if no negotiation had happened.

 

Fax Bypass Codec

The codec to use when the Fax Mode is set to Enable Bypass. Below are the selections in drop down menu This field does not apply to the AMR codec.

codec
G711 ulaw: 64 kbps North American
G711 alaw: 64 kbps ITU

 

Fax Packet Redundancy

Provides Fax packet redundancy to guard against network packet loss. This is only applicable to Relay Fax Mode. This field does not apply to the AMR or EVRC codecs.

No Redundancy - Original Payload is NOT duplicated

Redundancy Level 1 - Original payload is duplicated one time.

Redundancy Level 2 - Original payload is duplicated two times.

Redundancy Level 3 - Original payload is duplicated three times

 

Digit Relay

This setting specifies the method used to propagate DTMF digits. The Digit Relay field does not apply to the AMR codec.

DTMF In-band - Digits are sent in the same packets as voice.

DTMF Packetized - Digits are sent in a separate packet type (RTP Events as defined by RFC 2833) using the payload type specified by the Digit Relay Packet Type. If this field is set to DTMF packetized then the telephone event message will be sent in the CDR. Otherwise, the telephone event message will not be sent. See example Below

 

Example of "telephone event" line in SDP

v=0

o=- 1643042763 1643042846 IN IP4 10.129.39.111

s=eyeBeam

c=IN IP4 10.129.39.111

t=0 0

m=audio 7118 RTP/AVP 0 3 8 18 5 101

a=alt:1 1 : A95B1E03 000000F5 10.129.39.111 7118

a=fmtp:101 0-15

a=rtpmap:101 telephone-event/8000

a=sendrecv

 

DTMF via Signaling - Digits are sent separately

Note: If the far end does not support what is configured for Digit Relay the 2020 IMG will send DTMF In-band. If this occurs, the call trace will indicate the following: 20:41:07.240 CALL(225) (00:0001:01) Falling Back to In-Band Digit Tx

 

DTMF Digit Mapping - The following is the mapping of received digits.

Event Decimal
0-9 0-9
* 10
# 11
A-D 12-15
Flash 16

 

Digit Relay Packet Type

This numeric value (96 - 127) defines the packet type used for Digit Relay. DTMF digit relay packet type is configurable to any value type in the range (96 - 127). The Default is 101 which is what most endpoints default to. However, since this setting is not negotiated during call setup, it is important that the 2020 IMG is configured to match the remote endpoint setting.

 

Modem Behavior

Bypass (Default) - Switches to another codec when in a modem call. The codec that it is switched to is specified in the Fax Bypass Codec field. For example, if you are using a low bit rate codec, such as G.729, a modem or fax call will probably not be successful. So in this case the 2020 IMG changes the codec to what is configured in the Fax Bypass Codec field. This functionality is not supported for the AMR codec.

Disabled:

 

Initial Media Inactivity Timer

This timer is started when the channel is setup/outseized. If no RTP packets are received for the configured amount of time configured in the Initial Media Inactivity Timer Value below, an event is generated to the signaling layers. The Default value for the Initial Media Inactivity Timer field is Disable. To Enable the Initial Media Inactivity Timer, click in the Initial Media Inactivity Timer field and select Enable from drop down menu. When the Initial Media Inactivity Timer field is enabled, the Initial Media Inactivity Timer Value field below it can now be modified. See below.

 

Initial Media Inactivity Timer Value (Default = 181 seconds)

Set the Initial Media Inactivity Timer Value by either adjusting the box on the sliding scale or click in the Value in Seconds box and enter the desired value

SC_Init_Media_Inact_en.png

Note: The Initial Media Inactivity Timer Value is hidden from the ClientView pane. Once the Initial Media Inactivity Timer field is enabled, the Initial Media Inactivity Timer Value field will open up.

 

Media Inactivity Timer

The Media Inactivity Timer is used to indicate that RTP packets have stopped flowing for the configured amount of time configured in the Media Inactivity Timer Value below. When RTP packets stop flowing for the configured amount of time, an event is generated to the signaling layers and the signaling releases the channel. The Default value for the Media Inactivity Timer field is Disable. To enable the Media Inactivity Timer, click in the Media Inactivity Timer field and select Enable from drop down menu. When the Media Inactivity Timer field is set to enabled, the Media Inactivity Timer Value field can now be modified. Refer to Media Inactivity Detection Support for more information

Disable - Media Inactivity Timer is disabled.

Enable - Media Inactivity Timer is enabled. The Initial Media Inactivity Timer Value below will need to be set.

 

Media Inactivity Timer Value (Default = 30 seconds)

Set the Media Inactivity Timer Value by either adjusting the box on the sliding scale or click in the Seconds box and enter the desired value. For reference, view the screen capture in the Initial Media Inactivity Timer Value field above.

Note: The Media Inactivity Timer Value is hidden from the ClientView pane. Once the Media Inactivity Timer field is enabled, the Media Inactivity Timer Value field will open up.

 

Comedia Mode

Disable - Feature disabled (Default)

Active - Applies to SIP only. Used when the 2020 IMG is behind a NAT and needs to send or accept SIP INVITE messages. The 2020 IMG will convey that it is behind a NAT to a distant endpoint via the SDP in the SIP INVITE message. By doing this, the 2020 IMG advertises to other gateways to change their RTP port and IP address and map it with the NAT by sending the direction attribute a=direction<active> in the SIP SDP.

Passive - Used when the 2020 IMG is on a public network and needs to allow calls to a distant endpoint that is behind a NAT. The 2020 IMG uses the Source IP and Ports of the incoming RTP, RTCP, and T38 packets as the Destination IP and Port of the outgoing RTP, RTCP, and T38 packets.

For more information, refer to Symmetric NAT Traversal topic.

 

Source Port Validate

Select from drop down menu whether to enable or disable Source Port Validate Feature.

Enable (Default) - RTP Source Port Validation is enabled and the source IP address and UDP port of the incoming RTP packet is examined to ensure that the packet came from the IP address and UDP port number that the 2020 IMG is transmitting RTP data to.

Disable - The feature is disabled

For more information, refer to RTP Source Port Validate topic.