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Cisco Bug: CSCtb85171 - CHOC PPP Serial interfaces stop forwarding traffic showing HDLC error-me

Last Modified

Feb 24, 2015

Products (1)

  • Cisco 7600 Series Routers

Known Affected Releases


Description (partial)


On 7600 with  SPA-4XCT3/DS0 running SRB5,  CHOC serial interfaces stop forwarding traffic even if the interfaces remain in UP/UP and several error messages appear in the RP log at same time:


%SPA_CHOC_DSX-3-HDLC_CTRL_ERR: SPA X/Y TX Partial Packet FIFO Underflow events on HDLC Controller were encountered.

But also these other error messages may appear:


-Traceback= 4010DC74 4010E1B8 4041C1D4 40414FE0 4016FAF0 40168994 4041BE24 40413248 40413D24 40413E44
%SPA_CHOC_DSX-3-SPA_SW_ERR: SPA on Subslot 0: HDLC controller device driver failure: Failed to unpack link record Software error was encountered.
-Traceback= 4010DC74 4010E1B8 40419E88 4041BE74 40413248 40413D24 40413E44

%SPA_CHOC_DSX-3-NULL_DATA_STRUCTURE: Failed to create vc idb on slot/bay:6/0. Port Number = 0.
-Traceback= 4010DC74 4010E1B8 40412A34 40412F78 40413D24 40413E44
%SIPSPA-6-OIR: Bay 0 SPA Power changed to Off
%SIPSPA-6-OIR: Bay 0 SPA OK changed to Off
%SIPSPA-6-OIR: Bay 0 SPA Power changed to On
 %SIPSPA-6-OIR: Bay 0 SPA OK changed to On
%SPA_PLUGIN-6-FIRMWARE_DOWNLOADING: SPA-4XCT3/DS0[6/0]: Downloading SPA firmware (bundled)...
%SPA_PLUGIN-6-FIRMWARE_APPS_DOWNLOADING: SPA-4XCT3/DS0[6/0]: Downloading SPA firmware application (bundled)...


It is observed many controller, line and link flaps just right before the time of the issue:

%LINK-3-UPDOWN: Interface Serial xxxxx  changed state to up/down
%CONTROLLER-5-UPDOWN:  Controller T3 xxxxx  changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial xxxx changed state to up/down
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