Charging issues on Fluke 990 CopperPro test set.
Category Archives: Notes
2022 Telecom Reading List
The #Telecom reading list for this year; including books on Submarine Cable Systems, the history of Cable & Wireless, Alcatel Lucent’s downfall and SS7.
Ubuntu Cloned VMs getting Duplicate IPs (and yes – the MAC Addresses are unique)
Short mystery regarding cloned Ubuntu VMs with different MAC Addresses being allocated the same IP Addresses by DHCP.
Diff + Wireshark
Comparing packet contents with Wireshark and a diff utility
Offtopic – HDMI & USB over Twisted Pair
Long HDMI and USB cables using Cat5e
Being mean to Mikrotiks – Pushing SMB File Share
A Mikrotik is not a NAS. Or is it?
No.
Adding SNMP to anything with Redis and Python
Bolting an SNMP Server and stats collection onto your existing Python projects.
My 2021 Telco Reading List for the Holidays
My holiday reading list for 2020.
LTE (4G) – TMSI & GUTI
We’ve already touched on how subscribers are authenticated to the network, how the network is authenticated to subscribers and how the key hierarchy works for encryption of user data and control plane data. If the IMSI was broadcast in the clear over the air, anyone listening would have the unique identifier of the subscriber nearby … Continue reading LTE (4G) – TMSI & GUTI
IMTx: NET02x (4G Network Essentials) – Mobility Management – 3. Processing Location Updates
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. Let’s look at how the Tracking Area Updates work from the point of view of the network. Let’s take an example of a … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 3. Processing Location Updates
IMTx: NET02x (4G Network Essentials) – Mobility Management – 4. Changing MME and SGW
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we’ve seen earlier, the eNB needs a connection to an MME and a S-GW. However different eNBs may connect to different S-GWs … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 4. Changing MME and SGW
IMTx: NET02x (4G Network Essentials) – Mobility Management – 2. Balancing Location Update Load
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we saw before larger Tracking Areas minimize the number of UEs between terminals to update their location. The problem is the cells/eNBs … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 2. Balancing Location Update Load
IMTx: NET02x (4G Network Essentials) – Mobility Management – 1. Managing Location
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we saw with the Network Triggered Service Request, the network needs to know which eNB / cell the UE is currently being … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 1. Managing Location
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 3. Standby Modes
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we discussed before when no data has been sent by a UE for a period of time the eNB will switch from … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 3. Standby Modes
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 4. UE Triggered Service Request
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we just saw when a terminal moves to ECC-Idle while in EMM-Registered state, it releases it’s radio resources, so what happens when … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 4. UE Triggered Service Request
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 2. UE Connection to the Network
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. One of the common themes we cover over and over in the 4G discussion is the desire to preserve energy on the UE … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 2. UE Connection to the Network
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 1. Attach and Detach Procedures
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. A LTE UE has permanent IP connectivity for as long as it is connected. As soon as the UE powers up it requests … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 1. Attach and Detach Procedures
IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 7. NAS and Global View of Protocol Stack
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. The LTE architecture compartmentalises the roles in the mobile network. For example the eNB concentrates on radio connection management, while the MME focuses … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 7. NAS and Global View of Protocol Stack
IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 5/6. S1AP Connection
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. Each MME can manage millions of UEs. To handle this load the requirements of each subscriber for the MME must be as minimal … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 5/6. S1AP Connection
IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 3. Identifying & Managing Tunnels
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we’ve talked about traffic to and from UEs is encapsulated in GTP-U tunnels, with the idea that by encapsulating data destined for … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 3. Identifying & Managing Tunnels
Random Posts on Notes
SIP Extensions – RFC4474
Kamailio Bytes – Databases
SIM / Smart Card Deep Dive – Part 3 – APDUs and Hello Card
The case for Header Compression in VoIP/VoLTE
RTP – More than you wanted to know
What is a SIP Registrar?
Kamailio Bytes – Dialplan Module
RTPengine – Installation & Configuration
Adding USB-C Charging to an old ThinkPad
