A first router comprising processing circuitry configured to: receive, from a first client device connected to the first router via a first Open Systems Interconnection, OSI, Model Layer-2, L2, network , an L2 frame destined for a second client device , the L2 frame comprising an L2 header and a non-session-based payload , wherein the first router is connected to a second router via an OSI Model Layer-3, L3, network , and wherein the second router is connected to the second client device via a second L2 network ; identify, based on the L2 header of the L2 frame, an L3 network service associated with the L2 frame; generate, in response to determining the L2 frame comprises the non-session-based payload, a placeholder session identifier for the L2 frame, wherein the placeholder session identifier comprises a placeholder source IP address , a placeholder source port , a placeholder destination IP address , a placeholder destination port , and a first network protocol ; form an L3 packet comprising: an L3 header , wherein the L3 header comprises a source Internet Protocol, IP, address and a source port of the first router, a destination IP address and a destination port of the second router, and a second network protocol , the second network protocol selected based on the identified L3 network service associated with the L2 frame from a plurality of network protocols ; a payload comprising the L2 frame ; and metadata comprising the placeholder session identifier ; and perform, based on the placeholder session identifier, L3 session-based routing of the L3 packet to forward the L3 packet via the L3 network to the second router. receive, from a first client device connected to the first router via a first Open Systems Interconnection, OSI, Model Layer-2, L2, network , an L2 frame destined for a second client device , the L2 frame comprising an L2 header and a non-session-based payload , wherein the first router is connected to a second router via an OSI Model Layer-3, L3, network , and wherein the second router is connected to the second client device via a second L2 network ; identify, based on the L2 header of the L2 frame, an L3 network service associated with the L2 frame; generate, in response to determining the L2 frame comprises the non-session-based payload, a placeholder session identifier for the L2 frame, wherein the placeholder session identifier comprises a placeholder source IP address , a placeholder source port , a placeholder destination IP address , a placeholder destination port , and a first network protocol ; form an L3 packet comprising: an L3 header , wherein the L3 header comprises a source Internet Protocol, IP, address and a source port of the first router, a destination IP address and a destination port of the second router, and a second network protocol , the second network protocol selected based on the identified L3 network service associated with the L2 frame from a plurality of network protocols ; a payload comprising the L2 frame ; and metadata comprising the placeholder session identifier ; and an L3 header , wherein the L3 header comprises a source Internet Protocol, IP, address and a source port of the first router, a destination IP address and a destination port of the second router, and a second network protocol , the second network protocol selected based on the identified L3 network service associated with the L2 frame from a plurality of network protocols ; a payload comprising the L2 frame ; and metadata comprising the placeholder session identifier ; and perform, based on the placeholder session identifier, L3 session-based routing of the L3 packet to forward the L3 packet via the L3 network to the second router. <EOS>