rem: return hash_code %= TABLE_ENTRIES;
context: int old_hash( str  call_id, str cseq_nr ){   int  hash_code = 0;   int  i;    if ( call_id.len>0 )      for( i=0 ; i<call_id.len ; hash_code+=call_id.s[i++]  );    if ( cseq_nr.len>0 )      for( i=0 ; i<cseq_nr.len ; hash_code+=cseq_nr.s[i++] );   return hash_code %= TABLE_ENTRIES;}