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New Member

Available Bandwidth statement

When I do show interface serial command on router I’m getting a statement “Available Bandwidth 576 kilobits/sec” I would like to know what that mean.

The port speed is Fractional T1 and I have single DLCI with 512K.

When I set the bandwidth on main interface to 512K and do the show interface command the “Available Bandwidth statement” show 384kilobits/sec available.


interface Serial0/1

bandwidth 512

But, if I set the bandwidth to 768K on interface I’m getting a statement “Available Bandwidth 576 kilobits/sec”


interface Serial0/1

bandwidth 768

I would like to know what Available Bandwidth statement mean and what significant of available bandwidth 384K or/and 576K showing in available bandwidth statement.

Any suggestions welcome.


Output Example when bandwidth set to 768 in s0/1.

Serial0/1 is up, line protocol is up

Hardware is PQUICC with Fractional T1 CSU/DSU

MTU 1500 bytes, BW 768 Kbit, DLY 20000 usec,

reliability 255/255, txload 2/255, rxload 1/255

Encapsulation FRAME-RELAY IETF, loopback not set

Keepalive set (10 sec)

LMI enq sent 29, LMI stat recvd 29, LMI upd recvd 0, DTE LMI up

LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0

LMI DLCI 1023 LMI type is CISCO frame relay DTE

Broadcast queue 0/64, broadcasts sent/dropped 76/0, interface broadcasts 71

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 00:04:47

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: weighted fair

Output queue: 0/1000/64/0 (size/max total/threshold/drops)

Conversations 0/61/256 (active/max active/max total)

Reserved Conversations 0/0 (allocated/max allocated)

Available Bandwidth 576 kilobits/sec

5 minute input rate 5000 bits/sec, 6 packets/sec

5 minute output rate 9000 bits/sec, 7 packets/sec

1482 packets input, 268034 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

3 input errors, 2 CRC, 1 frame, 0 overrun, 0 ignored, 0 abort

1624 packets output, 243558 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

New Member

Re: Available Bandwidth statement

The Available Bandwidth statement is information and has nothing to do with the ACTUAL bandwidth.

Read here:

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