diff --git a/lib/if.h b/lib/if.h
index b3d14ba..9796a4d 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -131,6 +131,63 @@
 };
 #endif /* HAVE_PROC_NET_DEV */
 
+/* Here are "non-official" architectural constants. */
+#define TE_EXT_MASK             0x0FFFFFFF
+#define TE_EXT_ANORMAL          0x80000000
+#define LOSS_PRECISION          0.000003
+#define TE_KILO_BIT             1000
+#define TE_BYTE                 8
+#define DEFAULT_BANDWIDTH       10000
+#define MAX_CLASS_TYPE          8
+#define MAX_PKT_LOSS            50.331642
+
+/* Link Parameters Status: 0: unset, 1: set, */
+#define LP_UNSET                0x0000
+#define LP_TE                   0x0001
+#define LP_MAX_BW               0x0002
+#define LP_MAX_RSV_BW           0x0004
+#define LP_UNRSV_BW             0x0008
+#define LP_ADM_GRP              0x0010
+#define LP_RMT_AS               0x0020
+#define LP_DELAY                0x0040
+#define LP_MM_DELAY             0x0080
+#define LP_DELAY_VAR            0x0100
+#define LP_PKT_LOSS             0x0200
+#define LP_RES_BW               0x0400
+#define LP_AVA_BW               0x0800
+#define LP_USE_BW               0x1000
+
+#define IS_PARAM_UNSET(lp, st) !(lp->lp_status & st)
+#define IS_PARAM_SET(lp, st) (lp->lp_status & st)
+#define IS_LINK_PARAMS_SET(lp) (lp->lp_status != LP_UNSET)
+
+#define SET_PARAM(lp, st) (lp->lp_status) |= (st)
+#define UNSET_PARAM(lp, st) (lp->lp_status) &= ~(st)
+#define RESET_LINK_PARAM(lp) (lp->lp_status = LP_UNSET)
+
+/* Link Parameters for Traffic Engineering */
+struct if_link_params {
+  u_int32_t lp_status;   /* Status of Link Parameters: */
+  u_int32_t te_metric;   /* Traffic Engineering metric */
+  float max_bw;          /* Maximum Bandwidth */
+  float max_rsv_bw;      /* Maximum Reservable Bandwidth */
+  float unrsv_bw[MAX_CLASS_TYPE];     /* Unreserved Bandwidth per Class Type (8) */
+  u_int32_t admin_grp;   /* Administrative group */
+  u_int32_t rmt_as;      /* Remote AS number */
+  struct in_addr rmt_ip; /* Remote IP address */
+  u_int32_t av_delay;    /* Link Average Delay */
+  u_int32_t min_delay;   /* Link Min Delay */
+  u_int32_t max_delay;   /* Link Max Delay */
+  u_int32_t delay_var;   /* Link Delay Variation */
+  float pkt_loss;        /* Link Packet Loss */
+  float res_bw;          /* Residual Bandwidth */
+  float ava_bw;          /* Available Bandwidth */
+  float use_bw;          /* Utilized Bandwidth */
+};
+
+#define INTERFACE_LINK_PARAMS_SIZE   sizeof(struct if_link_params)
+#define HAS_LINK_PARAMS(ifp)  ((ifp)->link_params != NULL)
+
 /* Interface structure */
 struct interface 
 {
@@ -172,6 +229,9 @@
   /* interface bandwidth, kbits */
   unsigned int bandwidth;
   
+  /* Link parameters for Traffic Engineering */
+  struct if_link_params *link_params;
+
   /* description of the interface. */
   char *desc;			
 
@@ -389,6 +449,10 @@
 extern char *if_indextoname (ifindex_t, char *);
 #endif
 
+/* link parameters */
+struct if_link_params *if_link_params_get (struct interface *);
+void if_link_params_free (struct interface *);
+
 /* Exported variables. */
 extern struct list *iflist;
 extern struct cmd_element interface_desc_cmd;