Hi Mike
Yes in E// system we make the EDGE config on TG by assigning the 64 for edge and 16 for GPRS, but in ZTE iBSC we cannot assign 16 or 64 the system does the packing itself based on the type of PDTCH whether its “EDGE enabled” or “GPRS enabled” you can only choose EDGE or GPRS. This low throughput is in a particular BSC or in the whole nw.
If in some BSC then Plz check the DSP utilization of the BSC, the UPBB Board of the iBSC has the DSP’s and each DSP can support around 50 channels of PD so plz check if the DSP are overloaded or not as we also faced similar problem in our NW which was later resolved by balancing the DSP also in iBSC we can configure as many PD on a cell even when there is only a single E1 for the site but the Abis becomes the bottleneck there so check that also for some sites where many PD channels are defined but still low throughput