Venice Beach, Los Angeles, California, USA [© F2014]


We showed in Part 2 of this series of articles that after an UE (e.g., 5G smartphone) finishes its Registration Procedures with a 5G System (5GS), the Session Management Function (SMF) in the 5GS’ Service Based Architecture (SBA) control plane coordinates the setup of a Packet Data Unit (PDU) session along the data path involving the User Equipment (UE), the gNB (5G New Radio), and the UPF (User Plane Function) so that the UE can now access to the Data Network (DN) its specified in the PDU Session Establishment.

One of the key artifacts created from the PDU Session Establishment…

Harvard’s Widener Library, Cambridge, MA, USA [© F2018]


SSH Tunneling is very useful for SSH client and server to utilize remote and local resources respectively over an established SSH login session. Broadly speaking, there are three types of SSH tunneling namely the:

  • Local Port Forwarding — Forwards a local connection from a client host to a remote SSH server host and then to the destination host port. This makes remote resources on the remote SSH server host accessible on the local client host. …

Brighton Beach, East Sussex, UK [© FB2016]


Part 1 of this article provides a quick overview of what is 5G mobile core network or 5GC. It covers SMF, AMF, PCF, QoS Flow, SDF, DRB, and AN_Tunnel and CN_Tunnels etc…. It also shows how a UE (User Equipment such as a 5G Smartphone) can establish a PDU session via a 5G new radio (gNB) to a Data Network (DN) for traffic exchange. For brevity, we left a lot of details from the article but did highlight some missing details in the Summary Section of the article.

This is Part 2 of the article where we will examine the…

Incheon, South Korea (view from Sheraton Incheon) [© F2013]


5G is certainly the loudest buzzword in the networking industry for the past few years. Many carriers announced their 5G networks in 2019 but these 5G deployments were mostly based on the 3GPP Release 15. The specification still missed out many important 5G’s feature and service specifications such as the new 5G Core (5GC), cell densification, and support of network latency down to 1ms that are planned for the 3GPP Releases 16 and 17 to be standardized in 2020 and 2021 respectively.

Many of the 5G deployments announced in 2019 were deployed using the Non-Standalone 3x Option with the legacy…

The Bean, Millennium Park, Chicago, Illinois, USA [© B2013]


Not long ago, network equipment testing involves a lot of coordination with your colleagues to share and wire up the equipment in the lab before any testing can be started. With the popularity of network virtualization, all major vendors now offer virtualized version of their equipment in one form or another and many simple network equipment testing can now be simulated/emulated on a Windows PC.

This article describes how to setup GNS3 on a Windows PC to simulate/emulate an MPLS Pseudowire ePipe service between a Nokia 7750 and a Cisco 7200 routers. The only hardware required to run this interop…

Park 28 Panfilovtsev, Almaty, Kazakhstan [© B2010]


In my previous article, I showed how to setup and test layer 2 MPLS ePipe Pseudo Wire network service between Nokia 7750 and Cisco 7200 routers on a Windows 10 PC running GNS3. RSVP-TE and TLDP are used as the signalling protocols to establish the MPLS Transport and Service Tunnels respectively for the MPLS ePipe service. Since ePipe is a layer 2 network service, the virtual PCs connected at the two ends of the MPLS ePipe on GNS3 need to be on the same IP subnet in order for the PCs to ping to each other.

In this article, I…

Mont Des Arts, Brussels, Belgium [© B2014]


In the previous articles, I showed how to interop MPLS ePipe and VPRN network services between Nokia 7750 and Cisco 7200 routers on GNS3 ( on a Windows PC. In this blog, I will show how to config and verify Nokia 7750 and Juniper MX routers for MPLS VPLS (Virtual Private LAN Service) network service using a new PC-based network emulator software called EVE-NG (http://www/ EVE-NE is actually not a new kid in town. Its old name is UNETLAB and it has been around for a few years. …

Magapark OOD, Sofia, Bulgaria [© B2017]


In the previous blogs, I showed how to interop among Nokia, Cisco and Juniper routers for different MPLS layers 2 and 3 network services such as ePipe, VPLS and VPRN using GNS3 and EVE-NG network emulators on a Windows 10 PC. The articles demonstrate the flexibility and cost-effectiveness of network service design and and interop verification using a home PC. In order to make these articles within a reasonable length, the network design and router configs were kept to bare minimum to demonstrate the network services. Important network design details such as security, traffic engineering, resilience and service MTU etc……

Golden Gate Bridge, San Francisco, California, USA [© WB2018]


In my previous article, I showed how to setup layer 3 VPRN (or L3VPN) among Nokia 7750 and Cisco 7200 routers so that different IP subnets (e.g., PCs) served by a carrier’s IP/MPLS network can communicate. In fact, the carrier’s IP/MPLS network is shared by many different customers offering them with various L2 and L3 network services and each customer thought that they had their own private WAN network (i.e., VPN). The control plane of the VPRN PEs uses Multi-Protocol Internal Border Gateway Protocol (MP-iBGP) with vpn-ipv4 and/or vpn-ipv6 address families to exchange customers’ VPN routes, route targets (i.e., VPN…

National Museum, Riyadh, Saudi Arabia [© B2014]


Since 2000, carriers all over the world have been unifying their multi-silos Wide Area Networks (WAN) comprising ATM, TDM, Frame Relay, and IP etc… into a single QoS-ready MPLS WAN network to take advantages of the advance in silicone technology and the industrial standard protocols. The new MPLS WANs support different traffic types such as data, voice and video with QoS Service Level Agreements (SLAs), traffic engineering to maximize WAN network utilization, and less than 50ms network failure restoration.

The initial MPLS network design focuses on WAN with Provider Edges (PEs) as the MPLS service originating and terminating points. Attachment…

Derek Cheung

I live in Ottawa, Ontario Canada ( Some of my other remote memory backup is at ;-D

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