News: Wireshark is 20!

Impossible not to mention. Ethereal – these days known as Wireshark – is twenty! In 1998 Gerald Combs publicly released its first version 0.2.0. And he truly changed the IT (and particulary telco) world. Over the years Wireshark has won several industry awards, and it is one of the top-rated sniffers. Wireshark is a real gift for every engineer who works with a protocol stack. At the same time many BIG companies don’t even realize what contribution Wireshark means to their daily business!

 

Wireshark

 

Thank you Gerald and everyone who has helped with this great project!

Comment: Real-time communication & AI

So we have a first robot citizen. When we read about human-robots they are presented as future cleaning-ladies, news anchors, soldiers or sex-machines.

Everyone can imagine possible threats. In the current world of spam and fake news robots can manipulate our reality even in a more advanced way. It’s not just a robot shop assistant which – by the way – mentions how great is a new laundry detergent or your joy-robot asking for an upgrade in a (im)proper time. It can also spy what you have at home, how much time you spend with various activities, assess your income or overhear conversation with your spouse  – all, of course, in your best interest (let’s call it cookies 2.0). Not talking about real malware and ransomware.

In the same way participants in reality show forget about TV cameras, we’ll forget that robots are just robots. They don’t even need to look very real. Our brain is not that difficult to deceive. So the question is how to protect ourselves. At some point AI outsmarts human brain and we’ll need some help.

Let us know in comments section, what is your view and how to protect ourselves – e.g. how a new antispam sw/hw could look like.

SIP URI Overview

Everyone knows that SIP headers like R-URI, To, From, P-Asserted-Identity, Path, Route and others contain Uniform Resource Identifiers (URI) –  sip uri or tel uri. But do you know what formats we can use, with what parameters? As URI is one of the IP communication’s corner stones, it worth to have some better understanding.

SIP URI in VoLTE

Let’s start from the beginning. SIP URI is defined in RFC 3261, TEL URI in RFC 3966 (this RFC defines also modem and fax URL schemes).

SIP URI has a similar form to an email address. It contains typically a username and a hostname, for example test@realtimecommunication.info, where realtimecommunication.info is the domain of a SIP service provider. TEL URI is simply a telephone (landline or mobile) number as tel:+611234567890. It is needed mainly to support CS related scenarios and Mobile Number Portability (MNP). In practice we can see various forms of sip-uris:

sip:+611234567890@operator.com
sip:+611234567890@ims.mnc000.mcc000.3gppnetwork.org
sip:ims.mnc000.mcc000.3gppnetwork.org
tel:+611234567890
sip:+611234567890@ims.mnc000.mcc000.3gppnetwork.org;user=phone;npdi
tel:4567890;phone-context=+61123
tel:7890;phone-context=operator.com
sip:ffffffff@tas.ims.operator.com:5060;transport=udp

Last but not least we have also a SIPS URI, which specifies that the resource is to be contacted securely. For that we use TLS as a transport layer protocol. The format for a SIPS URI is the same, except that the scheme is “sips” instead of sip. Note, that any resource described by a SIP URI can be “upgraded” to a SIPS URI by just changing the scheme, if it is desired to communicate with that resource securely.

VoLTE Conference Call

Maybe you remember what I said about Group Messaging. That all the RCS deployments would be done faster without this feature. A similar thing we can say about VoLTE Conferencing. Ad-Hoc Multi Party Conference Call (CONF) is one of the basic requirements we have on VoLTE calling. Simply put each VoLTE network has to support conference calling. But to troubleshoot this great functionality can be a nightmare.

Ad-Hoc Multi Party Conference is one of the Supplementary Services supported by Telephony Application Server (TAS) (a dedicated Conference AS is an option too) and it is described in GSMA IR.92, which then refers to 3GPP TS 24.605 and 24.147. Today we’ll take a look at the conference call flow, along with the Mr’ interface between TAS and Media Resource Function (MRF).

Add participant button

Although we talk about conferencing, in fact it’s just a multi-party call. We don’t schedule any conference call for a given list of participants. We can only add additional numbers to an existing call. That’s why we describe the service as an ad-hoc conference. From the mobile operator point of view the conferencing service provides the means for a user to create, manage, terminate, join and leave conferences as well as the ability to update the involved parties. But most of the stuff is truly hidden to the end subscribers.

In general both voice and video conference can be supported, but only the support of audio media is required by VoLTE standard. The maximum number of participants differs network to network, usually it is between 6 and 10. Note, that the functionality is not limited to VoLTE users only, we can add to the call the CS users too.

News: Bitcoin and Mobile Networks?

Our current economy is digitized and generates an exponential growth of person-to-person (P2P) transactions. On the other hand we often face challenges around flexibility, trust, identity and authorization that existing financial instruments are sometimes struggling to address.

And that’s where blockchain comes into play. Blockchain is designed as a secure distributed system with high Byzantine fault tolerance. The most successful use cases for blockchain today are related to financial transactions and the management of financial assets. The most famous examples include Bitcoin, Ethereum, Ripple or Hyperledger.

Growth of Cryptocurrencies, © GSMA Intelligence 2018

GSMA Intelligence recently published a new issue of Global Mobile Radar, which analyzes the relationship of blockchain and mobile communications.

News: RTC in 2017

GSMA has just recently published the final numbers for 2017. As expected the last year we’ve seen less 4G deployments than in 2016.

4G Deployments in 2017

The only exception was the RCS. (Btw. GSMA released its Universal Profile Version 2.0 for Advanced RCS Messaging.)

From the population coverage point of view the last year meant a great step forward. Although many developing countries have been still more focused on 3G (4G coverage is on average 35% there), the overall number of 4G coverage increased significantly.

Population Coverage, © GSMA Intelligence 2017

The main reasons for that are:

• China has achieved 99% coverage in less than three years and it is now 4G-first
• In India Reliance Jio has beem driving the technological move towards 4G and other operators are following

Technology Migration© GSMA Intelligence 2017

Multimedia in VoLTE

It’s very interesting (and well, a bit suspicious) that the main focus of most VoLTE textbooks and trainings is signalling. But from the user-point-of-view, it is the voice data, what matters. As an end-subscriber I don’t care about signalling. My only interest is the call quality. But times they are a changin and engineers are asking about how to improve the overall voice-call quality and user experience. Today we’ll go through the basics as jitter, mouth-to-ear delay, packet loss rate or MOS, needed for QoS analysis.

For real-time multimedia we used to have dedicated telephone/radio networks. That has changed and voice/video streams are transported over IP network now.

We should understand that these IP networks were originally designed for data transport. To transport data we prefer the best-effort service model, which allows an easy network scaling and simple routers’ logic. On the other hand we don’t care much if packets arrive in-order or what are the delays between particular packets. We simply wait until we receive a whole file. If any packet is lost, TCP will re-transmit it.

Packets in Data Networks

It’s a different story with the real-time communication services though. RTC applications are less sensitive to packet loss, but they are very sensitive to packet delay. Usage of IP data network as a carrier brings a lot of challenges which have to be addressed by media protocols and network elements.

News: Mobile IoT Deployments

The last time we discussed 5G and IMS. One of the main drivers for 5G is Machine-2-Machine (M2M) communication. But surely 5G is not the only technology which enables Internet of Things (IoT). Many operators already do support proprietary technologies such as SigFox or LoRaWAN. But there are also 3GPP standardized (Release 13) networks for IoT other than 5G. They are LTE-M and NB-IoT, and they both operate on licensed spectrum. These technologies came a bit later, however now it seems they are gaining momentum.

On GSMA pages you can now find an interactive map with the existing IoT deployments.

GSMA IoT Map, © GSMA 2017

Let’s compare LTE-M and NB-IoT and take a look how they can benefit us.

VoIMS – IMS and 5G

Update:

This post is getting a bit rusty over the time. I plan to create some new stuff. Meanwhile I’d recommend to check GSMA IMS Profile for Voice, Video and Messaging over 5GS. And for those who want to know more 3GPP TR 23.700-10 Study on enhanced IMS to 5GC integration.

Maybe you have already heard about some features as Dynamical Network Slicing, CloudRAN, Network-as-a-Services, …  Some basic 5G principals we’ll briefly discussed also in this post. However my question is: What will be the change from the real-time communication point of view? What will be the 5G calling look like? Is the IMS (IP Multimedia Services, don’t confuse with International Microwave Symposium) to stay in the operators’ networks?

5G Deployments Sep, 2019 by 5G Americas

Seems that at the first stage the change will be less dramatic than when we introduced 4G. 4G was in many ways a revolution, whereas 5G is “only” an evolution. In fact 4G and 5G, at least in the beginning, will coexist and complement one each other. Still 5G will have a big impact on our existing technologies and the way we work with telecommunication networks.

5GS + EPC + IMS

VoLTE Flows and CS Network

Before I’ll finish a new post about 5G I decided to take a break and create a presentation which would complement VoLTE Basic Flows.

VoLTE Flows and CS network from Karel Berkovec

Btw. I can’t find the option on slideshare which would allow to update the material .. does anyone know??