This particualr call flow has both X2 and S1 interface control plane signalling. So after reading the X2AP(TS 36423-840) and S1AP(TS 36413-840) protocol specs for hours, i could finally figure out the packet structures. Then, we had to figure out SCTP stack. Since all the controlling is done on SCTP. Some google search and some test programs told me that Linux kernel version 2.6 and above have SCTP stack built in. I got the lksctp stack from source forge, complied the kernal and zoom. God, I love linux. Well you can get SCTP for Mac too and i got it in my mac. Thanks NKE SCTP!
Well we had everything in hand, SCTP sockets up and running, S1 AP and X2AP request response packets and nice ubuntu and mac pc's to write and test scripts. After couple of hours of colourful C, we had our test programs ready. Hurray!! Below is what we implemented
Next aim to implement GTP-U header!! Will take some time and lot of reading. Office is pretty relaxing these days, might help in speeding up things.
8 comments:
Hey,
I am also trying to do something similar,but I want to simulate LTE handover based on signal level.
Can you please help me.
Well...not an eNB guy. Sorry!
can you share this code, please?
hey...i lost the code. Anyway the S1AP encoding was not correct!
When handover happens from one node to another, the point of attachment changes. The UE obtains new IP...and SGW acts as mobility anchor and route data to this new IP.
Please correct me?
UE ip will never change during handovers!
Hi all
I am implementing X2AP decoder and I should test it. Do you know where I can get X2AP captured traffic?
No idea Sergey!
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