AAL5 encapsulation and tx-ring-limit particle size

[ringwyrm]

(a) I see some documentation on Cisco's website that the particle size is 576 or 580 bytes, but I see other documentation that say only 512 is usable by the user and that the first 64 bytes in the first particle is reserved. Does anyone know what the truth is here?

(b) When does AAL5 encapsulation occur? Before or after the transmit-ring?

[wdrootz]

For cisco products transmit particle size of 576 bytes also was selected to cover about 90 percent of Internet packets.Refer http://www.cisco.com/en/US/products/hw/modules/ps2033/products_implementation_design_guide_chapter09186a0080199957.html#wp1037329 for more info.