cc_GetFrame( )

Description | Cautions | Example | Errors | See Also

Name:	int cc_GetFrame(linedev, rcvfrmptr)
Inputs:	LINEDEV linedev	line device handle for D channel
	L2_BLK *rcvfrmptr	pointer to the received frame buffer
Returns:	0 on success < 0 on failure
Includes:	cclib.h
Category:	Data link layer handling
Mode:	synchronous
Technology:	BRI/SC; PRI (excluding DPNSS)

Description

The cc_GetFrame( ) function retrieves the frame received by the application. This function is used after a CCEV_L2FRAME event is received. Each CCEV_L2FRAME event is associated with one frame. This function is used for the data link layer only.

To enable Layer 2 access, set parameter number 24 to 01 in the firmware parameter file. When Layer 2 access is enabled, only the cc_GetFrame( ) and cc_SndFrame( ) functions can be used ( no calls can be made).

Parameter	Description
linedev:	The line device handle for the D channel.
rcvfrmptr:	The pointer to the buffer where the received frame is to be stored. The L2_BLK data structure contains the retrieved frame. See Section 6.7. L2_BLK for a description of the data structure. See the Example code for details.

Cautions

• The cc_GetFrame( ) function is called only after a CCEV_L2FRAME event is received. Refer to the protocol-specific parameter file.
• This function is not supported for the BRI/2 board or for the PRI DPNSS protocol.

Example

#include <windows.h>   /* For Windows applications only */  
#include <stdio.h>  
#include <errno.h>  
#include "srllib.h"  
#include "dtilib.h"  
#include "cclib.h"  
   
/* Global variables */  
   
int  size = 8;  
LINEDEV  lbuf;  
L2_BLK;  rcvfrmptr;  
typedef long int (*EVTHDLRTYP)( );  
.  
.  
.  
int evt_hdlr( )  
{  
   int rc = 0;  
   int ldev = sr_getevtdev( );  
   unsigned long *ev_datap = (unsigned long *)sr_getevtdatap( );  
   int len = sr_getevtlen( );  
switch(sr_getevttype( ))   
   {  
     .  
     .  
     .  
     case CCEV_L2FRAME:                   /* New frame received */  
   
     if (rc = cc_GetFrame(ldev, &rcvfrmptr) != 0)  
     {  
     /* Process error condition */  
     }  
     else  
     /* Process the frame and call control function */  
     .  
     .  
     .  
   
     break;  
     .  
     .  
     }  
}

Errors

If the function returns a value < 0 to indicate failure, use the cc_CauseValue( ) function to retrieve the reason code for the failure. The cc_ResultMsg( ) function can be used to interpret the reason code. Error codes are defined in the files ccerr.h, isdnerr.h, and isdncmd.h.

Error codes from the cc_GetFrame( ) function include the following:

Error Code	Description
ERR_ISDN_LIB | E_ISNOINFO	Information not available

See Also

• cc_SndFrame( )

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