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IP and Mobile Trends and Education

 
05.2018

LTE and 5G Differences: Function Decomposition Between RAN and CN

Let’s take a quick look at some of the differences between LTE and 5G in the area of functional splits between RAN and Core Network. We show and discuss high level splits of selected functionalities of the main “network functions/nodes” in both systems (discussing it from the 3GPP RAN3 WG perspective) from which we can make some conclusions on the differences between those two systems.

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04.2018

IPSec tunnel between Cisco IOS router and AWS VPC. Static VTI and crypto map with HSRP redundancy.

Recently i was asked to advise in the following scenario: VPN tunnel between AWS VPC and Cisco IOS routers on DC prem. Nothing sophisticated but: Two ISR 4k, HSRP VPN redundancy, legacy crypto maps in production (several working vpns) and Static VTI (AWS). Two Crypto structures sourced from one HSRP. I have put the results on blog.

Author: Marcin Bialy
04.2018

Troubleshooting FMC and Firepower Sensor communication?

In this post we are going to focus on the scripts included in FTD and FMC operating systems that help to troubleshoot connections between FTD sensors and Firepower Management Center. As they are run from the “expert mode” (super user), it is better that you have a deep understanding of any potential impact on the […]

Author: Ivan Radev
04.2018

Grandmetric Winter Events – Summary

Today, I’d like to summarize the latest events that we took part in during this winter in Poznan, Poland: Network & Wireless Meetup #2: IoT Security and Protocols The first stop on our way was NWM Meetup, where we’ve decided to talk about Internet of Things. Our speakers have provided very interesting sessions to all our […]

04.2018

Dealing with Cisco Firepower Management Center (FMC) and Firepower sensor communication. Registration process.

This post should help you to understand the Firepower sensor registration in FMC process and uncover the communication specifics between firepower components. I will also give you some additional hints what to check to verify the registration. In order to make troubleshooting easier there will be dedicated troubleshooting post later on.   1. High level […]

Author: Ivan Radev
04.2018

Cisco IOS XE Static Credential Vulnerability (Catalyst Switches, ISR4k and ASR1k Routers)

Cisco has stated that there is a vulnerability in Cisco IOS XE 16.X version (bug does not affect releases prior IOS XE 16.X)  that allows remote attacker to log in to the system with privilege 15 with default username cisco. This bug affects the platforms supported by IOS XE software, inter alia following:   Catalyst […]

Author: Marcin Bialy
04.2018

What Multiple Access schemes are used in Wireless Systems?

Introduction Communication between devices is often discussed on link level, which means that the focus is on how two end points exchange information: what is the protocol, waveform, timing in sending messages etc. This however, does not take into account that there are other devices wanting to use the medium. Using the same medium by […]

03.2018

Cisco Viptela SD-WAN components and connectivity (Part-2)

This post is dedicated to provide an overview of the Viptela policies. We go into the the details of the various kinds of policies and the overall policy architecture. In our earlier post we had focused on Viptela concept, Viptela SD-WAN components and how to authenticate the vEdges to Viptela cloud and setup basic connectivity between sites.

Author: Jacek Ozga
03.2018

How does OFDM work?

After discussing the main wireless transmission concept (How wireless works?), main channel propagation phenomena (What is pathloss? and What is shadowing?), and antenna configurations (What is MIMO?), let’s now take a look at one of the most commonly used transmission scheme nowadays, namely Orthogonal Frequency Division Multiplexing (OFDM). But, before we explain why do we […]

03.2018

How does a switch work?

To explain how does a switch work, let me make an introduction to the subject by explaining background of TCP/IP stack layers, frame and the purpose of switch. This will help you to understand the exact operation of switch which is the main agenda here. To allow communication between billions of computer devices, intermediate network […]

Author: Marcin Bialy
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