NBX Guard Timer

[tekunishan]

Hello,
I am troubleshooting a customer's NBX 100 system, and they are currently experiencing calls dropping. They have a T-1 circuit, but the problem only seems to be affecting about 3 telephones. We have swapped phones, cords, pwr supplies, switch ports, etc. and have also checked port settings on switches.
Tech Support recommends that I talk with the provider and check the Guard Timer setting. I DON'T KNOW what this setting means. Everytime I talk to the provider, they state, "what's Guard Timer?" Is there anyway to explain this to them in layman's terms to help troubleshoot my issue? Thanks in advance!!

 

[RickPeLowney]

After looking at the Administrator Guide, the "Guard Time" is probably refering to the timeout value that controls the waiting period after a call completes, before the channel can be used for another outbound call fom the NBX system.

Hopefully that's some help.

 

[GoTellBigDaddy]

The NBX works with most T1's when the Guard Timer is set at 2300 ms. This is set on the DLC in NetSet when configuring the DLC for T1. Also the Wink Wait Timer is normally around 3000-3500 ms depending upon the CO type and distance to CO, equipment, etc.... Again, this setting is done in NetSet.

You need to match the CO signalling. CO's normally have/serve:

Wink ~ Immediate (digits pass immediately after WINK)

Wink ~ Delay (digits are sent after a short delay after the WINK)

 

[techguru69]

Could you pass on where you can find these settings in NetSet. I cannot seem to locate them.

Thanks.

Tallyho,
Mike

"Any society that needs disclaimers has too many lawyers."

 

[GoTellBigDaddy]

Okay- before you read this... remember: When in NetSet you always have the help icon which is ?

From your NetSet HELP button... here it is:

T1 Modify Group
Device Configuration > Digital Line Cards > Modify T1 Group

You can modify a T1 group as needed. You cannot remove an item from a group without moving it to another group.

NOTE: If the group you are modifying has a large number of channels in it, the NBX system must make a large number of updates to the system database after you click OK or Apply. You may experience a delay of up to one minute or more before the NBX NetSet utility responds.

To modify a group:


Select T1 Group List from the drop-down list.


Click Apply.


Select the group that you want and click Modify.


Make the modifications that you want. You can change any of these fields.



Field
Options


Group Name
A unique name that identifies this group. The name appears in lists to help you identify the group.

Channel Protocol
The protocol used on all channels in this group. For T1, the value must be E&M.

Direction
Controls whether this group can make calls or only accept calls.

Values:

In Only -- Only incoming calls are possible.

Two way -- Incoming and outgoing calls are allowed.

Start Type
The signaling method used to indicate the start of transmission.

Value:

Wink

Digit Collection
Specifies the type of digit collection the NBX system should expect from the CO.

Values:

DNIS/DID -- Indicates that the T1 Digital Line Card should expect either DNIS (Dialed Number Identification System) digits or DID (Direct Inward Dialing) digits. The number of digits to expect is set in the Called Party Digits (DNIS/DID) field, described later in this table.

DNISANI -- Indicates that the T1 Digital Line Card should expect DNIS digits followed by ANI (Automatic Number Identification) digits. The number of DNIS digits is set in the Called Party Digits (DNIS/DID) field and the number of ANI digits is set in the Calling Party Digits (ANI) field. Both of these fields are described later in this table.

*DNIS* (where * is a delimiter) -- Indicates that the T1 Digital Line Card should expect to receive, from the Central Office (CO), the DTMF (Dial Tone Multi Frequency) tones for a star (*) before and after the DNIS digits. This is useful if the number of digits that the CO sends varies.

*DNIS*ANI* -- Indicates that the T1 Digital Line Card should expect to receive, from the CO, the DTMF tones for an asterisk or star (*), followed by DNIS digits, followed by another star (*), followed by ANI digits, followed by another star (*).

*ANI*DNIS* -- Indicates that the T1 Digital Line Card should expect to receive, from the CO, the DTMF tones for an asterisk or star (*), followed by ANI digits, followed by another star (*), followed by DNIS digits, followed by another star (*).

Called Party Digits (DNIS/DID)
Enter a number (from 3 to 10) representing the number of digits provided by the LEC, CLEC, the local carrier, or the long-distance carrier. These digits represent the telephone number that a caller dials to access an extension in the NBX system.

Calling Party Digits (ANI)
Enter a number (from 3 to 10) representing the number of digits provided by the LEC, CLEC, the local carrier, or the long-distance carrier. These digits represent the telephone number from which the caller made the telephone call to the NBX system. Typically, set to 0.

Outgoing Call Digit Format
Specifies the default digit pattern that the NBX system sends to the telephone company's Central Office (CO) equipment over all channels in this group. You can modify individual channels to choose a different digit pattern

Values:

DNIS -- Channels in this group send DNIS (Dialed Number Identification System) digits to the CO.

DNISANI -- Channels in this group send DNIS digits followed by ANI (Automatic Number Identification) digits.

*DNIS* (where * is a delimiter) -- Channels in this group send the DTMF (Dial Tone Multi Frequency) tones for a star (*) before and after the DNIS digits. This is useful if the number of digits that the NBX system sends to the CO varies.

*DNIS*ANI* -- Channels in this group send the DTMF tones for a star (*), followed by DNIS digits, followed by another star (*), followed by ANI digits, followed by another star (*).

*ANI*DNIS* -- Channels in this group send the DTMF tones for a star (*), followed by ANI digits, followed by another star (*), followed by DNIS digits, followed by another star (*).

Trunk to Trunk
Select Unrestricted to enable incoming calls to be transferred to another line card port. For example, you would enable Trunk to Trunk transfers if you planned to connect a Voice Over IP (VOIP) gateway to a line card port and let callers use the system to access the telephone system from a remote location, and use it to make CO calls.

Calls over unrestricted trunks bypass the COS (Class of Service) checks and may represent a risk that valid toll charges could be avoided.

Calls over unrestricted trunks ring as internal calls. Call Detail Reporting can treat such calls as internal or external, as required.

On Line
Check the On Line check box to bring the channel online.

Timer Values
Values that control specific timing behaviors of the T1 channel, such as how long to wait for certain events.

To modify a value, select it in the list and enter the new value in the New Value field.

Only an experienced installer should modify a timer value.

NOTE: 3Com recommends that both the telephone company equipment and the NBX timer values be set to:

Guard Time: 2,200 milliseconds or greater

Wink Wait Time: 3,000 milliseconds

New Value
The new value, in milliseconds, for the selected timer. Only an experienced installer should modify a timer value.

Auto Ext
The extension to which an incoming call is directed when it arrives on a Digital Line Card channel and cannot be pretranslated and/or translated by the dial plan. You can assign a different Auto Ext for each period of the business day: Open, Closed, Lunch, and Other.

Extension 500 is the default Auto Attendant.

On Line
Check this check box to bring the group online.








Click Apply and verify your changes.


Click OK to close the dialog box.