ITP7613, PA-A3-8E1 IMA, Abnormal bandwidth display.

[Texas Hare]

i have been using the ITP7613 system and PA-A3-8E1 IMA.
i have question.

Co1#sh int ATM1/0/0
ATM1/0/0 is up, line protocol is up
  Hardware is IMA PA E1, address is 001b.2bf4.cec0 (bia 001b.2bf4.cec0)
  MTU 4470 bytes, sub MTU 4470, BW 1920000 Kbit, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 1/255

Co1#sh controller ATM1/0/0
ATM1/0/0: Port adaptor specific information
Hardware is E1 (1920Kbps) port adaptor
Framer is PMC PM7344, SAR is LSI ATMIZER II
Scrambling is Enabled
Clock Source = INTERNAL
National bits = 0x3F
linecode is HDB3
E1 Framing Mode:  pcm30 ADM format
LBO (Cablelength) is long gain43 120db
Facility Alarms:
        No Alarm

E1 bandwidth of standard is 2048000 Kbit, is this right?
But why displayed BW "1920000 Kbit" on ATM1/0/0 interface status and E1(1920K) ?
I've never change the Bandwidth option.

and

As of Cisco IOS Software Release 12.2 (refer to Cisco Bug ID CSCdt57977 (registered customers only) ),
the bandwidth displayed on ATM IMA T1 and E1 interfaces is 1536 kbpsand 1920 kbps, respectively.

is this true?

my ITP7613 system has using the 12.2 IOS version.

[paolo bevilacqua · Accepted solution]

Whatever is displayed, it's only an informational value.

Consequently, it will make no difference to practical use.

You can set it to the value you want.

[Texas Hare]

thankyou for answer.

why informational value is 1920000?  if shown bandwidth is 1920000,  real BW  is 2048000 Kbit ?

My customers have doubts about the shown E1 Bandwidth to different from real E1 Bandwidth.

[paolo bevilacqua · Accepted solution]

Neither value is correct. Actual bandwidht is much lower, do to ATM overhead.

Tell your customer there is nothign to worry about, and it doesn't matter.

[paolo bevilacqua · Accepted solution]

I want to thank you for the nice rating and add a more complete answer, sorry if I didn't before:

Your circuit physical speed is 1,920 Kbps, as seen in "show controllers". This is because you are using 30 DS0 timeslots in the E1, 30 * 64 = 1,920.

[Texas Hare]

Thank you very much for more answers.

Have a nice day!