ospfd: Fast OSPF convergence

When considering small networks that have extreme requirements on
availability and thus convergence delay, the timers given in the OSPF RFC
seem a little “conservative”, i.e., the delay between accepted LSAs and the
rate at which LSAs are sent.  Cisco introduced two commands 'timers throttle
lsa all’ and 'timers lsa arrival’, which allow operators to tune these
parameters.

I have been writing a patch to also support 'timers lsa arrival’ fully and
‘timers throttle lsa all’ (without the throttling part) also in quagga.

diff --git a/ospfd/ospf_flood.c b/ospfd/ospf_flood.c
index d0d446f7a6e4a3cbc0584a7ed837a4bd7161aa4e..e9f443111a2f4fe61d6c45cd65a20e55271951d8 100644 (file)
--- a/ospfd/ospf_flood.c
+++ b/ospfd/ospf_flood.c
@@ -284,7 +284,7 @@ ospf_flood (struct ospf *ospf, struct ospf_neighbor *nbr,
           ; /* Accept this LSA for quick LSDB resynchronization. */
         }
       else if (tv_cmp (tv_sub (recent_relative_time (), current->tv_recv),
-                      intms2tv (ospf->min_ls_arrival)) < 0)
+                      msec2tv (ospf->min_ls_arrival)) < 0)
         {
           if (IS_DEBUG_OSPF_EVENT)
            zlog_debug ("LSA[Flooding]: LSA is received recently.");

diff --git a/ospfd/ospf_lsa.c b/ospfd/ospf_lsa.c
index 62c455e7744056a8bfc2c742fc62598513aee80f..ec0eab5f0a3e11efd877258e6a3fa4f09f906375 100644 (file)
--- a/ospfd/ospf_lsa.c
+++ b/ospfd/ospf_lsa.c
@@ -97,25 +97,25 @@ tv_floor (struct timeval a)
 }
 
 struct timeval
-intms2tv (int a)
+int2tv (int a)
 {
   struct timeval ret;
 
-  ret.tv_sec = a/1000;
-  ret.tv_usec = (a%1000)*1000;
+  ret.tv_sec = a;
+  ret.tv_usec = 0;
 
   return ret;
 }
 
 struct timeval
-int2tv (int a)
+msec2tv (int a)
 {
   struct timeval ret;
 
-  ret.tv_sec = a;
-  ret.tv_usec = 0;
+  ret.tv_sec = a/1000;
+  ret.tv_usec = (a%1000) * 1000;
 
-  return ret;
+  return tv_adjust (ret);
 }
 
 struct timeval
@@ -156,9 +156,9 @@ ospf_lsa_refresh_delay (struct ospf_lsa *lsa)
   quagga_gettime (QUAGGA_CLK_MONOTONIC, &now);
   delta = tv_sub (now, lsa->tv_orig);
 
-  if (tv_cmp (delta, intms2tv (OSPF_MIN_LS_INTERVAL)) < 0)
+  if (tv_cmp (delta, msec2tv (OSPF_MIN_LS_INTERVAL)) < 0)
     {
-      delay = tv_ceil (tv_sub (intms2tv (OSPF_MIN_LS_INTERVAL), delta));
+      delay = tv_ceil (tv_sub (msec2tv (OSPF_MIN_LS_INTERVAL), delta));
 
       if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
         zlog_debug ("LSA[Type%d:%s]: Refresh timer delay %d seconds",

diff --git a/ospfd/ospf_lsa.h b/ospfd/ospf_lsa.h
index 0700d0d54657a3a786a44aac6a1531ee154c3541..f2c08b1b93566a1cfd0d0574e385546c19b4793f 100644 (file)
--- a/ospfd/ospf_lsa.h
+++ b/ospfd/ospf_lsa.h
@@ -236,8 +236,8 @@ struct as_external_lsa
 extern struct timeval tv_adjust (struct timeval);
 extern int tv_ceil (struct timeval);
 extern int tv_floor (struct timeval);
-extern struct timeval intms2tv (int);
 extern struct timeval int2tv (int);
+extern struct timeval msec2tv (int);
 extern struct timeval tv_add (struct timeval, struct timeval);
 extern struct timeval tv_sub (struct timeval, struct timeval);
 extern int tv_cmp (struct timeval, struct timeval);

diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c
index 4b9f1c651a5a7b8968fc32f572cb86a223c289f8..a714683b06f3dd346bb7a2af731b76aae3c645cb 100644 (file)
--- a/ospfd/ospf_packet.c
+++ b/ospfd/ospf_packet.c
@@ -2080,7 +2080,7 @@ ospf_ls_upd (struct ospf *ospf, struct ip *iph, struct ospf_header *ospfh,
              quagga_gettime (QUAGGA_CLK_MONOTONIC, &now);
              
              if (tv_cmp (tv_sub (now, current->tv_orig), 
-                         intms2tv (oi->ospf->min_ls_arrival)) >= 0)
+                         msec2tv (ospf->min_ls_arrival)) >= 0)
                /* Trap NSSA type later.*/
                ospf_ls_upd_send_lsa (nbr, current, OSPF_SEND_PACKET_DIRECT);
              DISCARD_LSA (lsa, 8);

diff --git a/ospfd/ospfd.c b/ospfd/ospfd.c
index 050cbad19611cf51161850e93393d1140ebf890e..5b5014eec8c1ca3999c94c85b2517672c527c176 100644 (file)
--- a/ospfd/ospfd.c
+++ b/ospfd/ospfd.c
@@ -248,16 +248,16 @@ ospf_new (u_short instance)
   new->default_metric = -1;
   new->ref_bandwidth = OSPF_DEFAULT_REF_BANDWIDTH;
 
+  /* LSA timers */
+  new->min_ls_interval = OSPF_MIN_LS_INTERVAL;
+  new->min_ls_arrival = OSPF_MIN_LS_ARRIVAL;
+
   /* SPF timer value init. */
   new->spf_delay = OSPF_SPF_DELAY_DEFAULT;
   new->spf_holdtime = OSPF_SPF_HOLDTIME_DEFAULT;
   new->spf_max_holdtime = OSPF_SPF_MAX_HOLDTIME_DEFAULT;
   new->spf_hold_multiplier = 1;
 
-  /* LSA timers value init */
-  new->min_ls_interval = OSPF_MIN_LS_INTERVAL;
-  new->min_ls_arrival = OSPF_MIN_LS_ARRIVAL;
-
   /* MaxAge init. */
   new->maxage_delay = OSPF_LSA_MAXAGE_REMOVE_DELAY_DEFAULT;
   new->maxage_lsa = route_table_init();

diff --git a/ospfd/ospfd.h b/ospfd/ospfd.h
index 0dc90c8ae01ebf2ca7d11b216696d2fb52d8aafa..95809306d6e0790d0a84925916ec667a4c5cc66f 100644 (file)
--- a/ospfd/ospfd.h
+++ b/ospfd/ospfd.h
@@ -181,16 +181,16 @@ struct ospf
 
 #define OSPF_STUB_MAX_METRIC_SUMMARY_COST      0x00ff0000
 
+  /* LSA timers */
+  unsigned int min_ls_interval; /* minimum delay between LSAs (in msec) */
+  unsigned int min_ls_arrival; /* minimum interarrival time between LSAs (in msec) */
+
   /* SPF parameters */
   unsigned int spf_delay;              /* SPF delay time. */
   unsigned int spf_holdtime;           /* SPF hold time. */
   unsigned int spf_max_holdtime;       /* SPF maximum-holdtime */
   unsigned int spf_hold_multiplier;    /* Adaptive multiplier for hold time */
   
-  /* LSA timer parameters */
-  unsigned int min_ls_interval; /* mininum delay between LSAs (in msec) */
-  unsigned int min_ls_arrival;         /* LSA minimum arrival in milliseconds. */
-
   int default_originate;               /* Default information originate. */
 #define DEFAULT_ORIGINATE_NONE         0
 #define DEFAULT_ORIGINATE_ZEBRA                1