Specifying Atm2 Iq Shaping Values - Juniper JUNOS 10.1 - CONFIGURATION GUIDE 1-2010 Configuration Manual

JUNOS 10.1 Network Interfaces Configuration Guide
Determine the actual rate in ATM1 interfaces when the desired rate is 3,000,000 bps:

Specifying ATM2 IQ Shaping Values

For ATM2 IQ OC3c interfaces, the maximum available rate is 100 percent of line
rate, or 135,600,000 bps. For ATM2 IQ OC12c interfaces, the maximum available
rate is 50 percent of line rate, or 271,273,396 bps. You can specify the rates in bits
per second or cells per second. Fractional shaping is accurate within 0.5 percent of
the desired rate.
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Defining the ATM Traffic-Shaping Profile
Because 108,480,000 bps is greater than 1/31 of OC3 ATM cell line rate:
actual-rate = (128 * 135,600,000.1) / (trunc ((128 * 135,600,000.1) /
108,480,000))
actual-rate = 17,356,800,013 / (trunc (17,356,800,013 / 108,480,000))
actual-rate = 17,356,800,013 / 160
actual-rate = 108,480,000 bps
OC12c:
271,263,396 bps * 0.8 = 217,010,716.8 bps
Because 217,010,716.8 bps is greater than 1/127 of OC12 ATM cell line rate:
actual-rate = (128 * 542,526,792.45) / (trunc ((128 *
542,526,792.45)/217,010,716.8))
actual-rate = 69,443,429,434 / (trunc (69,443,429,434 / 217,010,716.8))
actual-rate = 69,443,429,434 / 320
actual-rate = 217,010,717 bps
OC3c:
Because 3,000,000 bps is smaller than 1/31 of OC3 ATM cell line rate:
actual-rate= ( 1 / ( trunc ( line-rate / desired-rate ) + 1 ) ) * line-rate
actual-rate = ( 1 / ( trunc ( 135,631,698 / 3,000,000 ) + 1 ) ) * 135,631,698
actual-rate = ( 1 / ( 45 + 1 ) ) * 135,631,698
actual-rate = ( 1 / 46 ) * 135,631,698
actual-rate = 2,948,515 bps
OC12c:
Because 3,000,000 bps is smaller than 1/127 of OC12 ATM cell line rate:
actual-rate = ( 1 / ( trunc ( line-rate / desired-rate ) + 1 ) ) * line-rate
actual-rate = ( 1 / ( trunc (542,526,792 / 3,000,000 ) + 1 ) ) * 542,526,792
actual-rate = ( 1 / ( 180 + 1 ) ) * 542,526,792
actual-rate = ( 1 / 181 ) * 542,526,792
actual-rate = 2,997,386 bps