Ensuring Quality in IMS

A few corrections to the first revision

Here are a few corrections/clarifications I have been meaning to post. Most of these are due to inconsistencies between different R7 specifications, so they are not necessarily wrong, just outdated or not yet synchronized:

Chapter 3

• Section 3.2.6 and Section 3.3.3 - there are some inconsistencies on communications between the A-BGF, the PDF, and the P-CSCF. This is very ambiguous in the R7 specs and has been somewhat cleared up in R8. I will post more on this at a later date.
• Figure 3.20 - Mj should be added to the circular interface showing the Gateway controller connection to itself (indicating an connection to other Gateway controllers). Mj is used for BGCF<->MGCF communication
• Table 3.18 - the MGCF<->BGCF interface should be Mj, not Mi as indicated in the table

Chapter 5

• Figure 5.3 - the "Isolation" diagram - the green line from the Device Emulation Box to the IP Centrex AS should be labled SIP, and the purple line should be labeled "Diameter"

IMS Interface Reference

In doing some final checks on the forthcoming IMS Poster follow-up to the book, I noticed there were several inconsistencies between our label interfaces in the Chapter 3 graphics and tables.

Rather than read thought the dozens of pages of 3GPP specs to check I did a quick check on a few of them and came across the latest Wikipedia entry for IMS here: http://en.wikipedia.org/wiki/IP_Multimedia_Subsystem

This is a great entry that I would recommend for use as a reference. It does not contain references to all of the R7 architecture (i.e. A-BGF is missing), but it looks like it covers R6 fairly well. In addition, all of the hotlinks make navaging the 3GPP specs a lot easier.

Look for some book corrections soon.