@conference {
	title = {Towards Reduced-State Service Chaining with Source Routing},
	author = {Papagianni, Chrysa. , Panagiotis, Papadimitriou., John S. Baras},
	year = {2018},
	month = {11/2018},
	abstract = {The widespread adoption of Network Function Virtualizatio~ (NFV) poses significant dataplane scalability limitations in datacenters (DC), as switches will be required to maintain a large amount of forwarding state for service chaining. This problem is exacerbated by the small Forwarding Information Base (FIB) of commodity switches, which are typically deployed in NFV infrastructures.
To mitigate this problem, we present a routing fabric that combines source routing with pathlet switching in order to (i) achieve state reduction and (ii) provide support for longer paths, hence, meeting the increased hop-count requirement of service chains. Coupling the proposed source routing fabric with a service chain embedding method, we achieve significant gains in terms of FIB consumption, request acceptance, and revenue generation.},
	address = {Rome, Italy},
	booktitle = {14th International Conference on Network and Service Management (NSM)2018}
}
@conference {
	title = {Rethinking Service Chain Embedding for Cellular Network Slicing},
	author = {Papagianni, Chrysa. , Panagiotis, Papadimitriou., Baras, John S.},
	year = {2018},
	month = {05/2018},
	abstract = {5G is set out to address the business contexts of 2020 and beyond, by enabling new network and service capabilities. The industry consensus is that 5G will facilitate ubiquitous connectivity seamlessly integrating wireless technologies and complementary communication networks while operators will be capable of providing networks on a need-for-service basis. Furthermore, there is a need for operators to exploit new revenue sources and break the traditional business model of a single network infrastructure ownership, by supporting multi-tenancy. Network slicing can provide a solution towards this end; it is considered a key for meeting 5G{\textquoteright}s diverse requirements, including future-proof scalability and flexibility.

Provisioning and management of network slices in the transition from Long Term Evolution (LTE) to the emerging 5G systems poses the need for the mapping of service chains that express traffic and processing requirements of LTE slices. In this respect, we follow a different approach to the service chain mapping problem, promoting virtualized network function (NF) sharing among multiple service chains that are associated with a certain network slice. Using mixed-integer linear programming formulations, we show that our approach leads to reduced NF State and management overhead, compared to the common resource allocation practice in virtualized Radio Access Networks.},
	address = {Zurich, Switzerland},
	booktitle = {IFIP Networking 2018},
	pages = {253-261}
}
@conference {
	title = {Network Function Placement on Virtualized Cellular Cores},
	author = {Dietrich, David., Papagianni, Chrysa. , Panagiotis, Papadimitriou., Baras, John S.},
	year = {2017},
	month = {01/2017},
	abstract = {The proliferation of mobiles devices, application sprawl, and the ever-increasing data volume generates significant~stress on cellular networks and particularly on the cellular~core, also known as the Evolved Packet Core (EPC). This is~further exacerbated by the deployment of hardware appliances~for the implementation of a wide range of network functions~(e.g., gateways, mobility management, firewalls, network address~translation), hindering any opportunity for elastic provisioning,~and eventually leading to high operational costs and a significant~degree of load imbalance across the EPC.~Network Function Virtualization (NFV) has been seen a ~promising solution in order to enable elasticity in the cellular core. Applying NFV to the EPC raises the need for network~function (NF) placement, which in turn entails significant challenges,~due to the stringent delay budgets among cellular core components and the coexistence of communicating data and~control plane elements. To address these challenges, we present a~linear programming (LP) formulation for the computation of NF~placements that strikes a balance between optimality and time
complexity. Our evaluation results show that the LP achieves~significantly better load balancing, request acceptance rate,~and resource utilization compared to a greedy algorithm that~performs NF placement inline with carriers{\textquoteright} common practice~today.~},
	address = {Bengaluru, India},
	booktitle = {9th International Conference on COMmunication Systems \& NETworkS (COMSNETS 2017)},
	pages = {pp. 259-266}
}
@article {
	title = {Near-Optimal Placement of Virtualized EPC Functions with Latency Bounds},
	author = {Dietrich, David., Papagianni, Chrysa. , Panagiotis, Papadimitriou., John S. Baras},
	abstract = {The proliferation of mobiles devices, application sprawl, and
the ever-increasing data volume generates significant stress on cellular
networks and particularly on the cellular core, also known as the
Evolved Packet Core (EPC), i.e., the cellular network component residing
between the radio access network and the Internet. This is further
exacerbated by the deployment of hardware appliances for the implementation
of a wide range of network functions (e.g., gateways, mobility
management, firewalls, network address translation), hindering any
opportunity for elastic provisioning, and eventually leading to high operational
costs and a significant degree of load imbalance across the EPC.
Network Function Virtualization (NFV) has been seen a promising
solution in order to enable elasticity in the cellular core. Applying NFV
to the EPC raises the need for network function (NF) placement, which
in turn entails significant challenges, due to the stringent delay budgets
among cellular core components and the coexistence of communicating
data and control plane elements. To address these challenges, we
present a linear programming (LP) formulation for the computation of
NF placements that strikes a balance between optimality and time complexity.
Our evaluation results show that the LP achieves significantly
better load balancing, request acceptance rate, and resource utilization
compared to a greedy algorithm that performs NF placement inline with
carriers{\textquoteright} common practice today.},
	pages = {200-222},
	volume = {10340},
	journal = {Communication Systems and Networks, Series: Computer Communication Networks and Telecommunications}
}
