ISDN L2 Bad Frame

Worked through lab 2.19 but I cannot get the ISDN status to be MULTIPLE_FRAME_ESTABLISHED.  I'm stuck at layer 2 with status TEI. Don't have this problem on BR2's E1. Any ideas?

 

# debug isdn q921

Dec  4 20:57:58.250: ISDN Se0/0/0:23 Q921: User RX <- BAD FRAME(0x00017F)
Dec  4 20:57:59.250: ISDN Se0/0/0:23 Q921: User RX <- BAD FRAME(0x00017F)
Dec  4 20:58:00.250: ISDN Se0/0/0:23 Q921: User RX <- BAD FRAME(0x00017F)

BR1

# show isdn status

Global ISDN Switchtype = primary-ni

%Q.931 is backhauled to CCM MANAGER 0x0003 on DSL 0. Layer 3 output may not apply

ISDN Serial0/0/0:23 interface
    dsl 0, interface ISDN Switchtype = primary-ni
    L2 Protocol = Q.921 0x0000  L3 Protocol(s) = CCM MANAGER 0x0003
    Layer 1 Status:
    ACTIVE
    Layer 2 Status:
    TEI = 0, Ces = 1, SAPI = 0, State = TEI_ASSIGNED


# show run | sec controller
controller T1 0/0/0
 framing esf
 linecode b8zs
 cablelength short 133
 pri-group timeslots 1-3,24 service mgcp
 description PRI

# show run | sec Serial
interface Serial0/0/0:23
 description PRI
 no ip address
 encapsulation hdlc
 isdn switch-type primary-ni
 isdn incoming-voice voice
 isdn bind-l3 ccm-manager
 no cdp enable


PSTN router

controller T1 0/0/0
 clock source internal
 cablelength short 133
 pri-group timeslots 1-3,24
 description PRI

interface Serial0/2/0:23
 description PRI
 no ip address
 encapsulation hdlc
 isdn switch-type primary-ni
 isdn incoming-voice voice
 isdn bchan-number-order ascending
 no cdp enable

PSTN#deb isdn q921
debug isdn q921 is        ON.
PSTN#term mon
PSTN#
Dec  4 21:54:51.090: ISDN Se0/0/0:23 Q921: Net TX -> SABMEp sapi=0 tei=0
Dec  4 21:54:55.590: ISDN Se0/2/0:23 Q921: L2_EstablishDataLink: sending SABME
Dec  4 21:54:55.590: ISDN Se0/2/0:23 Q921: User TX -> SABMEp sapi=0 tei=0
Dec  4 21:54:56.590: ISDN Se0/2/0:23 Q921: User TX -> SABMEp sapi=0 tei=0
Dec  4 21:54:57.090: ISDN Se0/0/0:23 Q921: L2_EstablishDataLink: sending SABME
Dec  4 21:54:57.090: ISDN Se0/0/0:23 Q921: Net TX -> SABMEp sapi=0 tei=0
Dec  4 21:54:57.590: ISDN Se0/2/0:23 Q921: User TX -> SABMEp sapi=0 tei=0
Dec  4 21:54:58.090: ISDN Se0/0/0:23 Q921: Net TX -> SABMEp sapi=0 tei=0

 

Comments

  • Hello Mark,

     

    I'll reply again with a more detailed explanation, but try a reload on your Br1 router,  and if that does not fix it, then as well as a reload of your PSTN router, and this should resolve your issue.

  • One thing I noticed is I forgot 'isdn protocol-emulate network' on ser0/2/0:23 of the PSTN router.  After adding this I'm seeing the following q921 debug on br1..

    r1-hq#


    Dec  4 22:08:58.358: ISDN Se0/0/0:23 Q921: User RX <- SABMEp sapi=0 tei=0

    Dec  4 22:08:58.358: ISDN Se0/0/0:23 Q921: S4_SABME: BACKHAULED & vsc_wants_L2_up = FALSE

    Dec  4 22:08:59.358: ISDN Se0/0/0:23 Q921: User RX <- SABMEp sapi=0 tei=0

    Dec  4 22:08:59.358: ISDN Se0/0/0:23 Q921: S4_SABME: BACKHAULED & vsc_wants_L2_up = FALSE

    Dec  4 22:09:05.358: ISDN Se0/0/0:23 Q921: User RX <- SABMEp sapi=0 tei=0

    Dec  4 22:09:05.358: ISDN Se0/0/0:23 Q921: S4_SABME: BACKHAULED & vsc_wants_L2_up = FALSE

    Dec  4 22:09:06.358: ISDN Se0/0/0:23 Q921: User RX <- SABMEp sapi=0 tei=0

    Dec  4 22:09:06.358: ISDN Se0/0/0:23 Q921: S4_SABME: BACKHAULED & vsc_wants_L2_up = FALSE

  • Hey, is your ccm-manager still backhauled?

     

    either way, try:

     

    no mgcp

    then

    mgcp

     

    if that doesnt work the next step is removing the bindings (l3, media, control) and readding them

     

    THEN rejigging with the no mgcp/mgcp.

     

     

  • Josh,

    Here is something interesting to note. I completely removed serial 0/0/0:23 interface and the pri-group from controller t1 0/0/0. If I reboot the router and build the t1 controller on br1 as shown below the PRI comes up fine.  

     


    controller T1 0/0/0

     framing esf

     linecode b8zs

     cablelength short 133

     pri-group timeslots 1-3,24  <--- 'service mgcp' not included

     description PRI


    If tear out the serial 0/0/0:23 config again, reboot, and build the controller's pri-group with 'service mgcp' I am stuck in status TEI. 

     

  • Got it.  Thanks guys.. Ripping everything out and re-adding worked.  Man, that's scary beause in the real lab I imagine these odd behaviors can really get in the way.

Sign In or Register to comment.