Here’s a list of some opensource EPCs. It may be useful to some people.
OpenAirInterface (eurocom) EPC: https://gitlab.eurecom.fr/oai/openair-cn
Corenet: https://github.com/mitshell/corenet
NextEPC: http://nextepc.org
Opencord’s vEPC: https://gerrit.opencord.org/#/admin/projects/vEPC
srsEPC (srsLTE): https://github.com/srsLTE/srsLTE
Feel free to comment with more EPC projects to be added here. Thanks 