Huawei Technologies Cisco Ciena Corporation Huawei Technologies The Path Computation Element (PCE) Communication Protocol (PCEP) provides mechanisms for PCEs to perform path computation in response to a Path Computation Client (PCC) request. The Stateful PCE extensions allow stateful control of Multi-Protocol Label Switching (MPLS) Traffic Engineering (TE) Label Switched Paths (LSPs) using PCEP. A Path Computation Client (PCC) can synchronize LSP state information to a Stateful Path Computation Element (PCE). A PCC can have multiple PCEP sessions towards multiple PCEs. There are some use cases, where an inter-PCE stateful communication can bring additional resiliency in the design, for instance when some PCC-PCE session fails. This document describes the procedures to allow stateful communication between PCEs for various use-cases and also the procedures to prevent computations loops.