EX2200 buffer overflows leading to dropped packets?

Hi all,

Trying to debug a problem with dropped packets from our firewall cluster; the cluster members are both connected to an EX2200 switch. When I look at the output of show interfaces <int> extensive on one of the firewall ints, I see the following sort of drops:

Egress queues: 8 supported, 4 in use
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 best-effort                    0           9868942044              9784947
    1 assured-forw                   0                    0                    0
    5 expedited-fo                   0                    0                    0
    7 network-cont                   0              4261145                    0

 Then I looked at the output of show interfaces queue <int>, and saw this output:

Egress queues: 8 supported, 4 in use
Queue: 0, Forwarding classes: best-effort
  Queued:
  Transmitted:
    Packets              :            9872164091
    Bytes                :         9429934422345
    Tail-dropped packets :               9790369
    RL-dropped packets   :                     0
    RL-dropped bytes     :                     0
Queue: 1, Forwarding classes: assured-forwarding
  Queued:
  Transmitted:
    Packets              :                     0
    Bytes                :                     0
    Tail-dropped packets :                     0
    RL-dropped packets   :                     0
    RL-dropped bytes     :                     0
Queue: 5, Forwarding classes: expedited-forwarding
  Queued:
  Transmitted:
    Packets              :                     0
    Bytes                :                     0
    Tail-dropped packets :                     0
    RL-dropped packets   :                     0
    RL-dropped bytes     :                     0
Queue: 7, Forwarding classes: network-control
  Queued:
  Transmitted:
    Packets              :               4261833
    Bytes                :             348050796
    Tail-dropped packets :                     0
    RL-dropped packets   :                     0
    RL-dropped bytes     :                     0

So in looking up the cause of "Tail-dropped packets", the Juniper tech article said that it was most likely the result of a packet buffer overflow. My question is, what kind of buffers do the EX2200 have, are they shared between port groups, and can an EX2200 sustain line-rate 1G/sec flows or not? (All the input and output NICs from the firewall are 1G)

TLR - experiencing dropped packets on an interface, suspect buffer overflows, how to fix?