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729GP and Univerge 3C Interop

Introduction

The purpose of this document is to detail the configuration of the Tellabs ONT 729GP for proper interoperability with the NEC Softswitch.

Document Number

ENG-010548

Applies To

Tellabs ONT 729GP.
All Tellabs OLTs (1150/1134/OLT2)
NEC Univerge 3C Softswitch

The 729GP is compatible with the NEC Univerge 3C on the latest versions of the FP29.2 and above branches of the OLT software. The 729GP is approved on system release 31.1.3 AppLits which includes OLT software release 31.1_601032 and above.

Assumptions

This document only covers the configuration needed for proper interoperability with the NEC Softswitch. The document assumes the following is true:

TConfig is Set Up: TConfig is the Tellabs Configuration tool for voice and is a part of the EMS software. TConfig should configured properly and operational on the OLT prior to starting this AppNote. If TConfig has not been set up, or you are unsure of its status see ENG-010473 Configuring Softswitch Voice found on the portal. Execute only the portions associated with TConfig Setup. Prior to starting this procedure, you should have verified that the ONT 729GP has an IP address and can successfully download configuration data from the EMS.
EMS is reachable from the ONT: The EMS TConfig tool must be able to communicate with the EMS either via having a routed path to the ONT, or a secondary NIC on the voice VLAN. This is necessary for XML file download which is sent from the EMS directly to the 729GP ONT.
DHCP Server Present on the Network: There must be an operational DHCP server on the VLAN designated for voice. The ONTs only support DHCP.
Optional DNS Server: If you intend to use hostnames, then a DHCP server must be defined on the voice network, and it must have entries to resolve the needed hostnames. If only IP addresses are used for reaching the Softswitch then the DNS Server is required. The DNS server entries if used must be configured in DHCP to hand the DNS entries to the ONT. DHCP is the only mechanism supported for communicating the DNS server IPs to the ONT.
Voice Cable: The 729GP has a RJ21 amphenol 24 pair connector. You will need a cable and some mechanism to terminate the pairs to RJ11 connectors.

Certificate Configuration

If TLS is used to encrypt the SIP channel, which is typical with MLPP enabled, you will need to install certificates on the 729GP, the OLT, and the EMS. Each 729GP does mutual authentication and requires that each 729GP have a unique certificate and that the certificate include the Hostname/Tconfig ID of the 729GP. This ensures that every device has it’s own unique certificate and authentication will fail if not properly set up.

Please see the following sections of ENG-010473 Configuring Softswitch Voice and execute the steps found there to set up the certificates and encryption:

Encrypted Voice
Voice Certificate Configuration
- MLPP and Encrypted Voice
Adding Device Certificates and Trust Anchors
Adding EMS Device Certificate
Adding OLT Certificates.

When these have been completed, the steps outlined below can be utilized to configure the lines on the device to interoperate with the NEC Univerge 3C Softswitch.

729GP Configuration

The Tellabs 729GP provides up to 24 lines of POTs analog appearances on the RJ21 Amphenol / AMPCHAMP connector. It interoperates with the NEC Softswitch via SIP. The following section will detail the configuration settings to be used for proper interoperability with the NEC Softswitch.

The Tellabs ONT is primarily configured via three standard profiles which define the connectivity to the switch and standard policies for voice lines. Most installations only require one or two sets of profiles based on usage.

The three profiles used by the system are:

Equipment Profile - This profile defines TConfig refresh interval, SIP timer settings and country code/region.
Service Profile - Service profiles define how to connect to the switch and the registrar. It also allows configuration of the RTP and SIP layer behaviors.
Call Features Profile - Defines the switch type, Dialing plan, Call features supported, hotline/warmline, etc.

Equipment Profile

The Equipment profile defines basic connectivity settings for the system. The default profile in most instances will work well for most users. It is recommended that the default profile be utilized. The Equipment Profile defines the following settings:

TConfig Refresh Interval - How often the voice line should poll the server for changes in the profiles. Default is once per day. This only affects global changes to profiles when no line changes have been performed.
SIP Timers - Allows configuration of Key SIP timers. Typically changes to this are not required.
Country Code - Allows configuration of the call progress tones and local impedance for the voice line to match other countries and regions. The default is US.

Detailed explanations for each field can be found in Tellabs documentation if modifications are required. Most installations only have a single Equipment Profile for all lines. Typically, the default equipment profile can be used without modification.

The default profile has the following characteristics:

Expects UDP operation on standard SIP port 5060.
Refresh profiles once per day (only affects global changes to profiles where no line change is made).
Sets the lines for US tones and impedances.

Refresh Mechanism: Always select Interval.
Refresh Interval: defaults to 1440 minutes, will pull config once every day from the Tconfig server.
Refresh Window: how long before the end of the interval to begin trying to pull the configuration data. Default is 60 minutes or one hour. Value MUST be less than ½ the Refresh interval.
SIP DSCP: Defines the DSCP marking for SIP packets.
SIP Timer T1: SIP packet round trip time estimate, defaults to 500 ms. Default value works in almost all scenarios and typically should not be changed.
SIP Timer T2: Maximum retransmission interval for non-INVITE requests and INVITE responses. Defaults to 4 seconds. Default value works in almost all scenarios and typically should not be changed.
SIP Invite Timeout: The maximum amount of time that the sender will wait for an INVITE message to be acknowledged.
SIP Non-Invite Timeout: The maximum amount of time the sender will wait for an non INVITE message to be acknowledged.
DBDT Address: only supported for Voice Gateway, not supported on Softswitch at this time, leave blank.
Region: Select the country. Defines the country or region to be used for generation of ringing, ringback and call alerting tones. Additional countries can be added in future releases based on customer requests.

The following Equipment Profile should be utilized when MLPP is utilized to ensure encryption of the SIP control link and verification of the connection via certificates.

When using TLS or Transport Layer Security to protect the SIP control path with encryption:

Transport Protocol Name: Set to TLS.
Transport Protocol Port: Automatically defaults to 5061 when TLS is selected. The port can be edited to match the tls port on the switch used for SIP.

Services Profile

The Services profile defines whether or not the voice line is set up for MLPP or not, defines packet markings for RTP, digits used for MLPP dialing, how to connect to the switch, and timers for the dial plan. Session timers can also be configured.

Most of the fields of the Services Profile can be left at the system defaults when utilizing UDP. Note that MLPP should never be enabled without using TLS.

The following fields should be modified:

Registrar URI: The registrar URI should be set to the IP address or hostname of the Softswitch. If a hostname is used, you MUST define a DNS server IP in the DHCP response so that the ONT can resolve the hostname into an IP address.
Proxy Address: The proxy address should be set to the IP address or hostname of the Softswitch. If a hostname is used, you MUST define a DNS server IP in the DHCP response so that the ONT can resolve the hostname into an IP address.
Outbound Proxy Address: The ONT 729GP REQUIRES the proxy to be set. The outbound proxy must conform to the following format:

The < and > represent less than and greater than signs. LR sets up the ONT for loose routing. If a hostname is used, you MUST define a DNS server IP in the DHCP response so that the ONT can resolve the hostname into an IP address.

RFC2833: RFC2833 defines a method for sending dialed digits via RFC2833. The 729GP supports either sending the digits inband or via 2833. Testing was performed with RFC2833 off.

Interdigit Timer - This timer defines how long the system will wait to consider dialing complete before sending the digits. A value of 8 seconds is recommended, but can be tuned to the sensibility of users. Some dial slowly, others want more responsivity.
Critical Timer - Defines the time to wait when there is a partial match on multiple patterns in the dial plan (such as when 7 digit and 10 digit dialing is supported). Digits are sent after a partial match is found and the Critical timer expires with no other digits dialed.
Timed Release - This defines the amount of time the line must be onhook before the call is terminated. Three seconds is the recommended setting.

Whenever MLPP is enabled or encryption of SIP or RTP is desired, the Services profile should be defined as follows:

MLPP: MLPP should be set to enabled wherever Multi-Level Priority and Pre-emption behavior is desired.
Dialing Prefix: This setting defines the prefix used to indicate which digit is used to prefix a priority digit used to define the priority of the call. It is typically 9 followed by a precedence digit and should not typically be changed. For special scenarios, it can be changed to another digit.
Priority Table: Defines for each dialed digit the associated precedence. This should typically not be modified.

Dial Prefix	Default Precedence	Level Allowed
94	0	Routine Only
93	2	Priority and below.
92	4	Immediate and Below
91	6	Flash and Below.
90	8	Flash Override and below.

Max Precedence Level: This defines the maximum value that will be allowed to be dialed on the line. The default is that the user is restricted to routine only. The user’s line should be modified to have the appropriate precedence. See the definitions on the table above for mapping of precedence to calling privileges.
QoS DSCP Priority: This field defines the priority for packet markings for SRTP packets to be sent from the device. The default markings agree with the UCR definitions for each call priority.
Media Encapsulation: Enable SRTP then disable RTP. This will ensure that unencrypted audio is not accepted by the system. SRTP or Secure RTP encrypts audio, RTP does not.
Security Policy: Most switches use the sip: scheme rather than the sips: scheme, the Best Effort policy relaxes the requirement and allows sip:. This setting should be left at the Best Effort Setting with the NEC Softswitch.
Registrar URI / Proxy Address: these should be set to either the Softswitch IP address, or to the hostname of the Softswitch. If hostnames are used, the DNS IP address MUST be setup on the DHCP server.
Network Domain: The network domain defines the domain for all SIP messages. The domain for most installations is uc.
Allowed Domains: The list of allowed domains to be used for MLPP.
Realm: It is critical that the realm on the switch and the domain configured here agree. Authentication will fail if the realm does not agree. The 729GP will NOT answer 401 Unauthorized challenges or 407 Proxy Authentication requests unless the realm in the challenge matches the configured realm on the 729GP.

Please consult the document ENG-010473 Configuring Softswitch Voice for definitions and settings for the other fields.

Call Features Profile

The Call Features profile defines for the ONT which services are allowed, the dial plan, any configuration needed for specific services such as hotline, warmline, call waiting, etc.

On most supported EMS versions, it will be necessary to create the Softswitch type on the General Tab.

Softswitch Name Full Form - Univerge3c
Softswitch Short Form - UV3C
Add + Apply - The user MUST press both Add followed by Apply so that the new Softswitch will be added. If Apply is not pressed, the entry will NOT be added.

It is recommended that two Call Features profiles be created, one with Call Waiting On, the other with Call Waiting Off. This allows control over whether the users can use these features. Most other features should be enabled and allow the switch to control them. Since Call Waiting is an endpoint function, it should be controlled at the ONT.

The following fields should be modified:

Softswitch Name - Select Univerge3c from the list created in the general tab for Softswitch name. The version field can be ignored.
Digit Map - Load the appropriate digit map for your installation. Typically, one of two profiles will be used:
- Standard-NorthAmerican-Telco-Dialplan - Defines a standard dial plan used for lines where it has a typical telco dialing plan for North America. Defines 7-digit dialing, 10-Digit Dialing, 911 with emergency headers, info numbers (211,311, etc), standard Vertical Service Codes.
- Dial Plan Changes - Dial plans can be quite complicated and Tellabs only supports changes to dial plans when any changes are made with the support of Tellabs TAC. Customer changes made without Tellabs TAC support must be supported by the user.
Enable CW - Recommend creating two Call Features Profiles, one with Call Waiting enabled (with -CW at the end of the profile name) and one with Call Waiting Disabled (with -NoCW at the end of the profile name). This allows control over which users have call waiting and which have no call waiting. Call waiting is typically DISABLED with MLPP. If Call Waiting is enabled along with MLPP, then calls of equal priority or lower will be allowed to generate call waiting tone and the user will be allowed to flip between the two calls with a flash hook. Leaving Call Waiting off gives standard MLPP behavior.
Hold - Recommend Hold is allowed on all profiles.
Enable 3WC - Enable Three-Way Calling for users. Typically, it can also be configured on the switch side so best to always enable it on the ONT voice ports.
Message Waiting - If the message waiting light or stutter dial tone is needed, it is controlled by this attribute. Message waiting MUST be properly configured on the switch for proper operation.
- Visual - Enables the message waiting light on phones that support FSK based message waiting lights. NEON and Voltage Based PBX message waiting lights are NOT supported.
- Audible - Enables the stutter dial tone indication for message waiting.
- Visual, Audible - Both stutter tone and the Visual message waiting indicator will be allowed. See notes above on the Visual indicator.
Enable Caller ID - Typically it should be set to Enabled. It can also be controlled on the switch, so enabling it allows it to be driven by the switch side. Enabling Caller ID with MLPP on, the system will also include an abbreviation at the beginning of the caller ID to indicate the call precedence level.

Voice Line Configuration

Once the profiles have been configured, the Voice Line Configuration is used to activate the voice lines of particular users.

The following fields need to be populated:

AOR URI: The AOR URI defines the voice line to the switch. It is of the form:

sip:<phone number>@<switch IP or hostname>

The AOR URI by default on NEC softswitches requires usage of the domain for logging into the switch. The Switch can be configured to respond to AORs that only have an IP in them, but it requires additional configuration on the switch.

The example shown above shows an AOR where the domain defined on the switch is nectellabs.net. Substitute the domain found on your switch.
Contact URI User: This will be auto populated by the EMS and match the phone number. Should not typically be modified.
Softswitch User - The username used to log into the switch. On most systems it is the directory number but varies by installation. Consult your switch admin for proper configuration.
Softswitch Password - The password sent to the switch as part of digest authentication of the switch line. The password will only be used if authentication is on and the switch challenges registrations or outgoing calls. The system requires that a password be entered, so enter a dummy password if authentication is off on the switch.
Services Profile - Select the services profile defined in the previous steps.
Call Features - Select the Call Features profile defined in the previous steps.
Apply - Press the Apply button to send the configuration to the ONT. The EMS will auto refresh the ONT and download the XML if any changes were made in this screen.

Enabling the Line

The line must then be enabled so that it will begin to register with the switch. This is done on the Status Tab of the line.

Press the Activate Button to enable the line and begin registration.
If the line is properly set up and the Softswitch properly configured, the user should see the line show Registered in the Registration State Field.

NEC Univerge 3C Configuration

The following section documents the configuration used for testing. This section simply covers one working example of many that can be configured on the NEC switch. This section is simply provided as a reference configuration to work from. NEC technical support should be consulted for any questions associated with the configuration of the NEC Softswitch.