| Title: | Digital Brouters Conference |
| Notice: | New common-code brouter family: RouteAbout, DECswitch 900 |
| Moderator: | MARVIN::HART LL |
| Created: | Mon Jul 17 1995 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 929 |
| Total number of notes: | 3736 |
RouteAbout Central EW/IP V1.1.003
FR>list circ 16
Circuit name = Sydney-Brisbane
Circuit state = Active Circuit is orphan = No
Frames transmitted = 300966 Bytes transmitted = 67805284
Frames received = 94022 Bytes received = 5907581
Total FECNs = 0 Total BECNs = 161
Times congested = 91 Times Inactive = 0
CIR in bits/second = 16000 Current Info Rate = 64000
Committed Burst (Bc) = 48000 Excess Burst (Be) = 0
Xmit frames dropped due to queue overflow = 1982 <<<<<<<
What is the cause of queue overflow?
Congestion on the frame relay network with BECN being received by the Central?
Or is it related to the output queue on the Frame Relay Interface (output
of "QUEUE" in "T 5")? Can the output queue length be increased?
Thanks
Dennis
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 806.1 | IAMOSI::LEUNG | Wed Mar 19 1997 17:15 | 4 | ||
Hmmm....., any FrameRelay RouteAbout Internal experts please reply. Thanks Dennis | |||||
| 806.2 | MARVIN::TURNER | Neil Turner IPEG REO, 830-4140 | Fri Mar 21 1997 03:29 | 68 | |
I suspect the queue overflow is probably being caused by the fact that the
network is becoming congested. However, do you have Bandwidth Reservation (BRS)
enabled on this interface/PVC? If you have then output overflows will occur when a
BRS class tries to transmit more than it's allocated bandwidth (and all other
classes are also using all their allocated bandwidth).
Assuming it is not BRS causing the output overflows the length of the output queues
cannot be altered, but the following commands are useful for seeing the current
length.
*t 5
CGW Operator Console
+queu
Input Queue Output Queue
Nt Interface Alloc Low Curr Fair Curr
0 Eth/0 100 50 100 30 1
1 MP/0 24 4 24 103 0
2 FR/0 24 4 24 103 0
The "Output Queue Fair" parameter indicates the maximum length of the
output queue before output discards will happen.
+buf
Input Buffers Buffer sizes Bytes
Nt Interface Req Alloc Low Curr Hdr Wrap Data Trail Total Alloc
0 Eth/0 100 100 50 100 24 62 1500 10 1596 159600
1 MP/0 24 24 4 24 22 62 2176 12 2272 54528
2 FR/0 24 24 4 24 22 62 2048 12 2144 51456
The above display shows the number of input buffers allocated to each
interface. The "Curr" value shows how many of them are currently free
and available to receive data. The "Low" entry in the low water mark for
these input buffers. If the number of free input buffers drops below this
value then the receive buffers are 'marked' to indicate that the receive
interface which owns this buffer is running out of receive buffers. If the
transmit code finds one of these buffers it will NOT add it to an output
queue the buffer is returned immediately to the input and an "Input Flow
Drop" is counted (see below). This may be happening in your case if due
to congestion in the FR network the output queue on the FR interface is
beginning to grow such that the ethernet interface is becoming starved
of buffers...
+err
Input Input Input Input Output Output
Nt Interface Discards Errors Unk Proto Flow Drop Discards Errors
0 Eth/0 0 0 176905 4 4 0
1 MP/0 0 0 0 0 0 0
2 FR/0 0 0 0 0 0 0
The following ELS messages are also logged when an output discards occur it
may be useful to check them.
+eve
Event Logging System user console
ELS>lis eve gw.057
Level: U-INFO
Message: Op ovfl nt %d int %s/%d
Active: Count: 4
ELS>lis eve gw.036
Level: U-INFO
Message: Op ovfl to hst %S nt %d int %s/%d
Active: Count: 0
Neil
| |||||
| 806.3 | 60689::LEUNG | Sun Mar 23 1997 22:41 | 49 | ||
>However, do you have Bandwidth Reservation (BRS) enabled on this interface/PVC?
No
*t 5
CGW Operator Console
+err
Input Input Input Input Output Output
Nt Interface Discards Errors Unk Proto Flow Drop Discards Errors
0 Eth/0 0 4 0 0 0 0
1 Eth/1 0 0 0 0 0 0
2 FR/0 0 0 0 0 27847 <<<< 0
3 PPP/0 0 0 0 0 0 0
4 PPP/1 0 0 0 0 0 0
5 PPP/2 0 0 0 0 0 0
6 PPP/3 0 0 0 0 0 0
7 PPP/4 0 0 0 0 0 0
8 PPP/5 0 0 0 0 0 0
9 PPP/6 0 0 0 0 0 0
+ queue
Input Queue Output Queue
Nt Interface Alloc Low Curr Fair Curr
0 Eth/0 100 50 99 30 1
1 Eth/1 100 50 100 30 0
2 FR/0 24 4 24 77 1
3 PPP/0 24 4 24 4 0
4 PPP/1 24 4 24 4 0
5 PPP/2 24 4 24 4 0
6 PPP/3 24 4 24 4 0
7 PPP/4 24 4 24 4 0
8 PPP/5 24 4 24 4 0
9 PPP/6 24 4 24 4 0
+buf
Input Buffers Buffer sizes Bytes
Nt Interface Req Alloc Low Curr Hdr Wrap Data Trail Total Alloc
0 Eth/0 100 100 50 93 20 62 1500 10 1592 159200
1 Eth/1 100 100 50 100 20 62 1500 10 1592 159200
2 FR/0 24 24 4 24 18 62 2048 12 2140 51360
3 PPP/0 24 24 4 24 18 62 2176 12 2268 54432
4 PPP/1 24 24 4 24 18 62 2176 12 2268 54432
5 PPP/2 24 24 4 24 18 62 2176 12 2268 54432
6 PPP/3 24 24 4 24 18 62 2176 12 2268 54432
7 PPP/4 24 24 4 24 18 62 2176 12 2268 54432
8 PPP/5 24 24 4 24 18 62 2176 12 2268 54432
9 PPP/6 24 24 4 24 18 62 2176 12 2268 54432
Will get ELS output at a later stage
| |||||