Signaling storm or false alarm?

Each time we use our mobile devices we can generate multiple signaling events within the mobile core. As a result, signaling traffic has risen at a faster clip than traditional mobile network traffic.
“The volume of signaling traffic is high, certainly, but it’s nothing that modern equipment isn’t able to handle,” said Chuck Wesley-James, senior product manager at Sonus. He said that throttling, flow control and congestion control are key for diameter signaling controllers, the network appliances that route diameter messages. “We want that central point to be the place where it’s going to stop that signaling flood,” he said.
Oracle estimates worldwide LTE diameter signaling traffic at about 12 million messages per second, and projects that this volume will increase to 99 million messages per second by 2017. By that time policy will account for 62% of signaling volumes, surpassing centralized routing and roaming. Policy is becoming the biggest source of signaling traffic, but it is not the fastest growing traffic source. Oracle says that distinction goes to online charging, which will grow at a compound average annual growth rate of 180% through 2017.
Many diameter signaling use cases are directly linked to LTE. But, as 3G networks incorporate more IP elements, diameter signaling is becoming important there as well. Network elements and functions that use diameter signaling include charging systems, policy servers, policy control enforcement points, mobility management entities and home subscriber servers. These may be hit by signaling storms in the larger networks, but the phenomenon is less common for smaller operators.
“I think it’s been overblown – this whole issue of the signaling storm,” said Anjan Ghosal, CEO of Diametriq. “I think the guys that are really getting overwhelmed with diameter traffic are really the tier-ones, the top 10 of 15 operators around the world. I have never seen that in the tier-two or tier-threes – I think it’s just fear that has been put into their minds by Tekelec.”
Tekelec, which was acquired by Oracle in 2013, has been the dominant vendor of diameter signaling solutions. But, in a market that is growing this quickly, there is room for many competitors. And as new use cases for diameter signaling evolve, smaller players are quickly staking their claims, especially when it comes to virtualization of diameter signaling control. Sonus notes that virtualization is increasingly important for carriers as a method of cost control.
“They’re into it because it’s saving money,” said Wesley-James. “It’s saving [operating expense], it’s allowing them a faster time to market. They’re able to reuse hardware that they already have and are using in the networks. As vendors our value-add going to virtualization is to let the carriers use the infrastructure they already have.”
For more on diameter signaling in mobile networks, watch the RCR Wireless News webinar, available on demand, and download our free feature report: Eye of the Storm.
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