Cisco Cisco IOS Software Release 12.4(4)T

Workaround: Bring the BRI interface UP by changing the switch-type from basic- qsig to basic-net3. 

CSCse81069

Symptoms: Unconfiguring the isdn service b_channel command is not taking effect. The command 
is not removed from the running configuration.

Conditions: This symptom occurs when configuring the isdn service b_channel command to a state 
other than the default value of 0 on the ISDN D channel.

Workaround: To remove the command, shut down the T1/E1 controller first and then unconfigure 
the command under the D channel serial interface. 

CSCse98867

Symptoms: A router may reload when a multilink bundle goes down while packets are flowing.

Conditions: This symptom is observed on a router that is configured for Multilink PPP (MLP) with 
hardware compression.

Workaround: There is no workaround. 

CSCsf03251

Symptoms: Primary and backup NFAS interfaces may transition from WAIT to OOS even after 
receiving “in-service” message from the PSTN.

Conditions: This symptom is observed on a Cisco AS5400XM that is running several Cisco IOS 
Release 12.4 mainline and Release 12.4T .

Workaround: There is no workaround. 

CSCsf96318

Symptoms: QSIG (ISO) call back (ring back) fails between a Cisco 3745 router and a Cisco 1760 
router.

Conditions: The call back fails.

Workaround: There is no workaround. 

CSCsg25693

Symptoms: Layer2 of BRI interfaces is not coming up, and it is in the “NOT Activated” state.

Conditions: This issue is seen in Cisco IOS interim Release 12.4(11.1)T.

Workaround: There is no workaround. 

CSCsg38412

Symptoms: When a PPP Multilink session is established over ISDN on a router running Cisco IOS 
version 12.2SB, IPCP fails to negotiate. When debug ppp negotiation is enabled, it shows that 
IPCP packets from the peer are not processed. The output of show interface for the ISDN D channel 
interface shows that the input queue limit is 0.

Conditions: This symptom is observed when the ISDN BRI or PRI interface is not configured as part 
of a dialer rotary-group or dialer pool, and RADIUS is used to assign the multilink bundle to a VRF.

Workaround: Use the dialer rotary-group command to assign the ISDN interface to a dialer. 

Cisco IOS Release 12.4(9)T1 is a rebuild release for Cisco IOS Release 12.4(9)T. The caveats in this 
section are resolved in Cisco IOS Release 12.4(9)T1 but may be open in previous Cisco IOS releases.