Here is the function for the relationship of Burst Tolerance BT (time) and Maximum Burst Size MBS (a number of cells).
Most switches allow you to set the MBS and then they calculate the BT based on this function.
Definitions: Ts = 1/SCR, Tr = 1/PCR, ts = BT
MBS = | 1 + ((CDVT + ts) / (Ts - Tr))
where |x| stands for the largest integer less than x. for Tr > 1 and CDVT > Tr -1.
This function is based on using a unit of micro-seconds for each variable. The corresponding function is used to calculate the maximum burst size B (a number of cells) on the PCR policing:
B = | 1 + ((CDVT) / (Tr - 1)) |
For Tr > 1 where |x| stands for the largest integer less than x. CDVT must be greater than Tr - 1.
This function is also based on units of micro-seconds. It breaks down if Tr < 1 microsecond. At that point a smaller unit of time would need to be subtracted from Tr instead of 1 microsecond. This only matters with very large PVCs with a PCR of over 1000000 cells per second.
These values for MBS and CDVT are usually defaulted for the user and the same default applies no matter what the SCR and PCR values are. Some ATM providers set the CDVT and MBS very low and adjust up if problems like you are observing appear.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.