This time I want to discuss one of the problems we see with Diameter and introduce a work being done to overcome this problem.
Capabilities exchange is one of the fundamental and most important mechanisms in Diameter, it is taking place in the beginning of each session, and allows peers to define the basic parameters/capabilities for the session (version number, supported Diameter apps, security mechanisms, etc…)
But what if the capabilities on one of the sides change during the session ? what if the sessions are being kept open for long time
and in this time an upgrade or configuration change in one of the clients/servers involved takes place ?
The way Capabilities exchange is defined in RFC 3588 is that it can take place only in the inception of a session, so if there is a change
during the session it means we need to tear down all the existing sessions involved and restarted in order for the updated capabilities to be taken into account – not very efficient you’ll agree.
But worry no more, the cure is on the way, a new IETF Diameter draft is here to help - The Diameter Capabilities Update Application.
A work led by Glen Zorn, whom is one of the driving forces behind Diameter since his Cisco days.
This work defines a new Diameter application intended to allow the dynamic update of a subset of Diameter peer capabilities over an
existing connection.
Because the new proposed Capabilities Update application operates over an existing transport connection, modifications of certain capabilities is prohibited.
There are a lot of heated discussions going on in the Diameter swamp around this new work – some security issues have being raised, but I think those will be handled also.
This is a blessed and important work (I can see all of you with Gx interface related work scars nodding your heads) and let’s hope we will have this draft approved soon.
I personally believe with service providers complaining on the amount of signaling in Diameter and the delays involved in some of sessions set up times – this new work is very important and sheds bright healthy light into one of the dark corners of the Diameter 3588 RFC.
Showing posts with label Diameter. Show all posts
Showing posts with label Diameter. Show all posts
5/2/09
Diameter implementations – not for the faint of heart
I want to share with you a few horror stories about some of the Diameter implementations we see out there.
We recently came across an implementation by one of the main network vendors where Diameter server is sending Diameter client messages – of course that the clients in the other end could not respond and some of them where getting quite mixed up with the unexpected message.
This is really the tip of the iceberg, Diameter is very flexible and in NGN the applications are still very young – a destructive combination it seems, so the way the standards are translated and implemented varies across different vendors.
It’s not only the network equipment providers, some of the operators have also joined the party, with in-house Diameter standards and requirements that have already gained quite a “notorious reputation” in where they taken the standards and their non conformance, I don’t want to name and shame anyone, but I’m sure some of you are nodding their heads with called sweat.
Is it becoming better ? well not really, LTE/SAE is being developed today, new cable standards, new ETSI TISPAN equipment, and there things aren’t better, development is starting before the interfaces are finalized, so sorry no good end to this post, I believe the interoperability issues will keep accompany us in the recent future and will affect the dream of open plug & play no silo networks.
We recently came across an implementation by one of the main network vendors where Diameter server is sending Diameter client messages – of course that the clients in the other end could not respond and some of them where getting quite mixed up with the unexpected message.
This is really the tip of the iceberg, Diameter is very flexible and in NGN the applications are still very young – a destructive combination it seems, so the way the standards are translated and implemented varies across different vendors.
It’s not only the network equipment providers, some of the operators have also joined the party, with in-house Diameter standards and requirements that have already gained quite a “notorious reputation” in where they taken the standards and their non conformance, I don’t want to name and shame anyone, but I’m sure some of you are nodding their heads with called sweat.
Is it becoming better ? well not really, LTE/SAE is being developed today, new cable standards, new ETSI TISPAN equipment, and there things aren’t better, development is starting before the interfaces are finalized, so sorry no good end to this post, I believe the interoperability issues will keep accompany us in the recent future and will affect the dream of open plug & play no silo networks.
2/21/09
Barcelona – thoughts in Layer 5
This week I been in the Mobile World Congress in Barcelona.
A lot of words were written about the show, by people with much more knowledge and better writing skills.
I will try to give another view of the show – not from the shiny handsets point of view, but from the Diameter view of things.
I think that from the network side there are three main trends/activities that are happening and have close symbiotic relationship with Diameter
The first one is Convergence, I know it’s been around since the millennium, but it’s really happening, maybe not because of the service transparency and new services, as much as the fact that it can save OPEX and CAPEX and create new revenues by opening new markets. Convergence requires a lot of Diameter, but also presents a huge challenge in the Diameter level – how to connect wireline and mobile infrastructure that use different Diameter standards, or how to connect mobile Diameter based equipment to ISP equipment that is still using RADIUS.
The second trend is LTE, it’s enough to see some of the press releases from Verizon, Ericsson and Alcatel-Lucent to understand that the industry is aligning behind the technology, and in 2010 we are expected to see the first roll outs.
LTE represent a all new set of Diameter interfaces, with brand new networks that are using (by the standard) more than 45 Diameter interfaces, Diameter is everywhere and actually not limited to the core anymore, it is moving out to the edges, up to the last mile – those Diameter interfaces are not out there yet – so what will NEP’s do – I guess as always – build their own semi standard interfaces – and will continue to sweat on interoperability and lock the operators
The last trend is the Cloud – some heavyweights such as IBM, are pushing it, and they see it taking over the telecom world.
Financially it makes sense, mainly with MVNO’s and small operators but also with the Tier-1’s that don’t want to spend billions on OPEX and CAPEX.
I think one of the main issues that I can see from that level is that there are going to be huge interoperability issues, and the datacenters will need to have Diameter Gateways in the entrance to the cloud to make sure the information can be spread inside the cloud with no vendor and standard lock-in.
There are a few more things that changed this year, such as UMA – one of the big trends of the last few years almost disappeared, and it seems that Mobile WiMax might be going in the same route, unless something drastic will change, most of the people I met weren’t’ optimistic on its future.
That it, next time I will try to dig in Diameter and LTE, what is new, and some of the challenges.
The second trend is LTE, it’s enough to see some of the press releases from Verizon, Ericsson and Alcatel-Lucent to understand that the industry is aligning behind the technology, and in 2010 we are expected to see the first roll outs.
LTE represent a all new set of Diameter interfaces, with brand new networks that are using (by the standard) more than 45 Diameter interfaces, Diameter is everywhere and actually not limited to the core anymore, it is moving out to the edges, up to the last mile – those Diameter interfaces are not out there yet – so what will NEP’s do – I guess as always – build their own semi standard interfaces – and will continue to sweat on interoperability and lock the operators
The last trend is the Cloud – some heavyweights such as IBM, are pushing it, and they see it taking over the telecom world.
Financially it makes sense, mainly with MVNO’s and small operators but also with the Tier-1’s that don’t want to spend billions on OPEX and CAPEX.
I think one of the main issues that I can see from that level is that there are going to be huge interoperability issues, and the datacenters will need to have Diameter Gateways in the entrance to the cloud to make sure the information can be spread inside the cloud with no vendor and standard lock-in.
There are a few more things that changed this year, such as UMA – one of the big trends of the last few years almost disappeared, and it seems that Mobile WiMax might be going in the same route, unless something drastic will change, most of the people I met weren’t’ optimistic on its future.
That it, next time I will try to dig in Diameter and LTE, what is new, and some of the challenges.
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