From 42c93dd71537de7d88d32e8a8e6ec56ee6c9be5a Mon Sep 17 00:00:00 2001 From: Tommaso Pecorella Date: Sun, 29 Jan 2012 01:14:23 +0100 Subject: [PATCH] Bug 1109 - Point out the effects of ArpCache::PendingQueueSize attribute --- src/internet/doc/internet-stack.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/internet/doc/internet-stack.rst b/src/internet/doc/internet-stack.rst index 23582c735..81cc7b32f 100644 --- a/src/internet/doc/internet-stack.rst +++ b/src/internet/doc/internet-stack.rst @@ -127,6 +127,16 @@ paired with an IPv4 representation of such device. In Linux, this class main purpose is to provide address-family specific information (addresses) about an interface. +All the classes have appropriate traces in order to track sent, received and lost packets. +The users is encouraged to use them so to find out if (and where) a packet is dropped. A +common mistake is to forget the effects of local queues when sending packets, e.g., the ARP +queue. This can be particularly puzzling when sending jumbo packets or packet bursts using UDP. +The ARP cache pending queue is limited (3 datagrams) and IP packets might be fragmented, easily +overfilling the ARP cache queue size. In those cases it is useful to increase the ARP cache +pending size to a proper value, e.g.::: + + Config::SetDefault ("ns3::ArpCache::PendingQueueSize", UintegerValue (MAX_BURST_SIZE/L2MTU*3)); + The IPv6 implementation follows a similar architecture. Layer-4 protocols and sockets