Buy or Renew
Buy or Renew
Cisco + Splunk: It’s a new day for your data. Learn more.
 
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 
cancel
Create a new article
748
Views
0
Helpful
0
Comments

An AS5400 IOS voice gateway sends two Progress Indicators (PIs) to the TDM switch, causing a call failure on the TDM switch

TCC_2
Level 10
Level 10

‎06-22-2009 05:07 PM - edited ‎03-12-2019 08:53 AM

Core Issue

Call Flow:
H225 setup     ISDN setup
  with 1 PI    with 2 PIs 

  ------originating gateway (OGW)----->terminating gateway (TGW)---->time-division multiplexing (TDM) Switch

Resolution

Sending two Progress Indicators (PIs) should not cause any call failure. A PI is optional information and can cause problems with busy-tone, ring-back tone, or an announcement but not an actual call failure.

It is fine to have two PIs in one message according to the Q.931 standard, section 4.5.23:

     "The purpose of the Progress Indicator information element is to describe an event which has occurred during the life of a call. The information element may occur two times in a message."

For more information, refer to:


0 Helpful
Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Customers Also Viewed These Support Documents