Anyhow, actually dimensioning of ISUP E1 per SS7 link is depends on its interconnecting type.
Another factor of calculating dimensioning of SS7 Channel capacity. We have to consider erlang recommendation. Let’s say one operator recommend to use 0.2 erlang for A link type and 0.4 erlang for F link type (this erlang recommendation could be different with each interconnecting type. Remember this erlang recommendation is only guided from operator