SIP FQDN Support

The Fully Qualified Domain Name (FQDN) feature supports entering a Fully Qualified Domain Name instead of an IP Address into the c= line of the SDP on the outgoing leg. If the outgoing Fully Qualified Domain Name (FQDN) is configured and then enabled in the SIP SGP Profile pane, the SIP Signaling and/or VoIP module IP addresses will be replaced with the FQDN in the outgoing request and/or outgoing SIP response. Follow the procedure below to configure FQDN on 2020 IMG.

Call Flows

Outgoing with FQDN Enabled

The call flow below displays an SS7 to SIP call flow where FQDN's is enabled.

CF_FQDN_Enabled.png

Incoming FQDN DNS Query

The call flow below displays the case where an incoming INVITE includes a c= line with a FQDN in place of an IP Address. In this case, a DNS query is executed before the call is established.

CF_FQDN_DNS_Query.png

Configuration Procedures:

Incoming support is always enabled and can not be modified. If the 2020 IMG receives an incoming INVITE with a Fully Qualified Domain Name (FQDN) in the SIP URI, a DNS query will be initiated. On the Outgoing side, the Fully Qualified Domain Name must be configured for the feature to initiate a DNS query. See configuration below.

Initial Configuration

The procedure below explains how to configure the 2020 IMG to execute a DNS Query on the outbound leg. Before configuring the outbound FQDN feature, the 2020 IMG must have an initial configuration created on it. Follow the Basic Configurations procedure before proceeding.

Create a DNS Server and DNS Client:

Create a DNS Server and DNS Client object. See Below.

  1. Right Click on 2020 IMG EMS object and select New External Network Elements. Refer to the External Network Element topic for more information on configuring this object.

  2. Right Click on the External Network Elements object and select New DNS Servers. Refer to DNS Servers topic for more information on configuring this object.

  3. Right Click on the DNS Servers object and select New DNS Server. Enter IP Address of this DNS server. Refer to DNS Server for more information.

  4. Right Click on 2020 IMG Name (Physical node) and select New DNS Client. The IP address will default to the IP address of the Ctrl Port. Select from drop down menu in the Primary DNS Server field the DNS Server just created. See DNS Client for more information.

 

Create SIP Profile (SGP)

  1. Create a SIP Profile. Right Click on 2020 IMG EMS and select New Profiles.FQDN

  2. Right Click on the Profiles object just created and select SIP SGP. Change the SIP Profile ID to something other than 0. This will allow other fields in this object to be modified. Click on the Outgoing Fully Qualified Domain Name field and select from drop down menu when the Fully Qualified Domain Name servers will be displayed. See screen capture below.

SC_FQDN_SGPConfig.png

 

Create SIP Signaling

  1. Right Click on 2020 IMG Name: and select New Signaling.  Refer to Signaling topic for more information on this object.

  2. Right Click on the Signaling object created and select New SIP. Refer to SIP Signaling topic for more information on this object.

  3. Enter a FQDN in the Fully Qualified Domain Name (FQDN) field. See screen capture below.

SC_FQDN_SIPSIGNALING.png

Create Remote Gateway

Through ClientView create external network element. To associate the SIP profile created with a remote SIP gateway, an external network element must be created. Follow procedure below to communicate with a remote gateway.

  1. Right Click on 2020 IMG EMS and select New External Network Elements. Refer to External Network Elements topic for more information.

  2. Right Click on External Network Elements and select New External Gateways. Refer to External Gateways for more information.

  3. Right Click on External Gateways and select New External Gateway. Select SIP as the Gateway Signaling Protocol and select the profile created for FQDN. Refer to External Gateway topic for more information.

  4. Once the External Network Elements are created, they can be associated with Channel Groups through IP Network Elements. See below

 

Insert SIP External Network Element into SIP Channel Group

  1. Right Click on the SIP Channel group created and select New IP Network Element. Within the IP Network Element field, select from drop down menu, the gateway created. See screen capture below.

 

Optional: SIP Virtual Address:

When configuring a SIP Virtual Address that will be utilizing the Fully Qualified Domain Name feature the Network Interface Object created for this SIP Virtual Address must have Gratuitous ARP and ARP Responses set to Disable. Below is procedure describing what would need to be accomplished if a SIP Virtual Address was being configured with a fully qualified domain name server. See SIP Virtual Address.

  1. Right Click on IP Network and select IP Address. In the Physical Interface field select CPU from drop down menu. Enter 'IP Address' for this interface and also enter Default Gateway ip address. Refer to IP Network Interfaces link for more information.

  2. Click In the Gratuitous ARP and ARP responses field select Disable from the drop down menu.

  3. Right Click on the SIP Signaling object created earlier and select New SIP Virtual Address. The SIP Virtual IP Address field will be automatically populated with the address of the interface just created. Refer to SIP Virtual Address for more information.

  4. Enter FQDN in the Fully Qualified Domain Name (FQDN) field. See Below

    SC_FQDN_SIP_Virt_Address.png


FQDN enabled but No FQDN Configured

If the outgoing FQDN options are enabled but no FQDN hostname is entered through WebUI then the 2020 IMG will transmit a WARNING!! and process the call normally with IPs. Below is the warning displayed and some scenarios that would generate this warning.

CT_FQDN_No_Hostname.png

Possible Issues

  1. Signaling ONLY option is enabled but NO IMG Signaling FQDN
    Local IMG Signaling IP of the IMG will be shown.

  2. SDP C Equal Line ONLY option is enabled but NO VoIP module FQDN
    Local VoIP module IP of the IMG will be shown

  3. Both option is enabled but NO IMG Signaling FQDN
    Local Signaling IP of the IMG will be shown
    FQDN of VoIP module (NOT IP) will be shown at SDP C equal line 

  4. Both option is enabled but NO VoIP module FQDN
    FQDN of the local IMG Signaling will be shown
    Local VoIP module IP of the IMG will be shown

Call Trace - FQDN Failure Message

If DNS is not configured or not configured properly, the call will fail responding with a 488 "Not Acceptable Here". Click on the following link for a call trace of the failure message. Call Trace Failure Message

RADIUS

VSAs

The following VSAs support the Fully Qualified Domain Name feature.

Refer to the RADIUS - Dialogic VSAs topic for more information.

Dictionary File

The radius dictionary file supports the FQDN feature. On a freeRADIUS server this file should be copied into /usr/share/freeradius directory.

Example INVITE Messages

Outgoing FQDN option = Signaling ONLY

When the Outgoing FQDN option is set to Signaling Only, the FQDN of the local 2020 IMG signaling IP address only is inserted in the outgoing SIP messages. Relevant lines are in bold.

<--- [10.129.39.123, 5060 <- 10.129.39.59, 5060]

INVITE sip:617@ma01dtran01.dialogic.com:5060 SIP/2.0

Via: SIP/2.0/UDP img1-dtran.dialogic.com:5060;rport;branch=z9hG4bK-53d0-1180551394-19996-487

Call-ID: 3085-400-4302007185634-Quincy-0@img1-dtran.dialogic.com

CSeq: 1 INVITE

Max-Forwards: 70

To: <sip:617@ma01dtran01.dialogic.com:5060>

From: unavailable<sip:unavailable@img1-dtran.dialogic.com>;tag=95ffcd055e0f78f7d5d397020e89288d3de1

User-Agent: Dialogic-SIP/10.3.3.68 Quincy 0

Contact: <sip:unavailable@img1-dtran.dialogic.com:5060>

Allow: INVITE, BYE, REGISTER, ACK, OPTIONS, CANCEL, SUBSCRIBE, NOTIFY, INFO, UPDATE

Supported: path, timer

Session-Expires: 1800

Expires: 300

Organization: Dialogic Corporation Inc

Content-Type: application/sdp

Content-Length: 187

   

v=0

o=Dialogic_SDP 0 0 IN IP4 img1-dtran.dialogic.com

s=Dialogic-SIP

c=IN IP4 10.129.39.32

t=0 0

m=audio 8000 RTP/AVP 0

a=rtpmap:0 PCMU/8000

a=silenceSupp:off - - - -

 

Outgoing FQDN option = SDP c equal line ONLY

When the Outgoing FQDN option is set to SDP c=line ONLY, the FQDN of the local IMG VoIP IP address only is inserted in the outgoing SIP messages. Relevant lines are in bold.

<--- [10.129.39.123, 5060 <- 10.129.39.59, 5060]

INVITE sip:617@ma01dtran01.dialogic.com:5060 SIP/2.0

Via: SIP/2.0/UDP 10.129.39.59:5060;rport;branch=z9hG4bK-53d0-1180551394-19996-487

Call-ID: 3085-400-4302007185634-Quincy-0@10.129.39.59

CSeq: 1 INVITE

Max-Forwards: 70

To: <sip:617@ma01dtran01.dialogic.com:5060>

From: unavailable<sip:unavailable@10.129.39.59>;tag=95ffcd055e0f78f7d5d397020e89288d3de1

User-Agent: Dialogic-SIP/10.3.3.68 Quincy 0

Contact: <sip:unavailable@10.129.39.59:5060>

Allow: INVITE, BYE, REGISTER, ACK, OPTIONS, CANCEL, SUBSCRIBE, NOTIFY, INFO, UPDATE

Supported: path, timer

Session-Expires: 1800

Expires: 300

Organization: Dialogic Corporation Inc

Content-Type: application/sdp

Content-Length: 187

 

v=0

o=Dialogic_SDP 0 0 IN IP4 10.129.39.59

s=Dialogic-SIP

c=IN img1-dtran-mod1@dialogic.com

t=0 0

m=audio 8000 RTP/AVP 0

a=rtpmap:0 PCMU/8000

a=silenceSupp:off - - - -

 

 

Outgoing FQDN option =Both

The following shows a SIP INVITE message when the Outgoing FQDN option is set to Both.

<--- [10.129.39.123, 5060 <- 10.129.39.59, 5060]

INVITE sip:617@ma01dtran01.dialogic.com:5060 SIP/2.0

Via: SIP/2.0/UDP img1-dtran.dialogic.com:5060;rport;branch=z9hG4bK-53d0-1180551394-19996-487

Call-ID: 3085-400-4302007185634-Quincy-0@img1-dtran.dialogic.com

CSeq: 1 INVITE

Max-Forwards: 70

To: <sip:617@ma01dtran01.dialogic.com:5060>

From: unavailable<sip:unavailable@img1-dtran.dialogic.com>;tag=95ffcd055e0f78f7d5d397020e89288d3de1

User-Agent: Dialogic-SIP/10.3.3.68 Quincy 0

Contact: <sip:unavailable@img1-dtran.dialogic.com:5060>

Allow: INVITE, BYE, REGISTER, ACK, OPTIONS, CANCEL, SUBSCRIBE, NOTIFY, INFO, UPDATE

Supported: path, timer

Session-Expires: 1800

Expires: 300

Organization: Dialogic Corporation Inc

Content-Type: application/sdp

Content-Length: 187

     

v=0

o=dialogic_SDP 0 0 IN IP4 img1-dtran.dialogic.com

s=dialogic-SIP

c=IN IP4 img1-dtran-mod1@dialogic.com

t=0 0

m=audio 8000 RTP/AVP 0

a=rtpmap:0 PCMU/8000

a=silenceSupp:off - - - -