This is another stories on router line card again...
In the past, there are different approach used to design network for pure ISP and for Telco MPLS network. The ISP here means either pure Internet Service Provider or internet part of big Telco network. While the Telco MPLS network means MPLS infrastructure for supporting GSM or CDMA operation.
The ISP usually requires less requirements compared to the Telco counterpart in terms of redundancy, packet processing capabilities, as well as pricing.
In terms of redundancy, for example, the ISP can tolerate two router in mated-pair redundant Routing Engine or Supervisor Engine. This means they just rely on box redundancy should one router fails, where router A can fail-over to Router B in case of failure or maintenance. Meanwhile, the Telco will push for both router (box) redundancy as well as Routing Engine / Supervisor Engine redundancy on each router. Thus, should one router engine fail, they can fail-over to its redundant Supervisor before going to fail-over to mated-pair box.
In terms of packet processing capability, the internet router (the ISP one), can sustain line rate processing at higher packet size (300B, 500B, 800B, etc) while the Telco tends to make it line rate at smaller packet size (64 B for example). This is due to average internet traffic size is bigger than average voice traffic.
Thus, when Telco start moving their GSM/CDMA traffic over IP, they tends to make perfect for everything with highest capability as possible.
The only part which ISP router demands more than Telco MPLS router may be on routing table size. Definitely ISP router needs to support full Internet routing tables while the average telco with 40M customers for example may only need to support 5000 entires of IGP in their routing table as requirement.
The other side to look at it is from financial or economic perspective. The Telco are CAPEX intensive environment. A moderate Telco with 50 Million subscriber can spend more than one billion USD per year for all their telco needs (cell site, land acquisition, L1 infrastructure, radio, PS Core, CS core, etc). Out of that 1 Billion USD, may be less than 5 percents are allocated to IP part (the routers and switches). Thus, the impact of saving on redundancy and line card are not really significant and the money is there basically. Meanwhile, ISP business are quite budget sensitive, where the cost are much smaller as well the revenue and does not have the luxury of that Telco counterpart. Their cost is easier to be mapped, for example for router, link and access-distribution. Thus, saving in router will impact their P&L more than the Telco part.
ISP is pure IP since the beginning, while the Telco were TDM minded from the start. Thus, when the Telco were moving to IP, a lot of questions were raised whether the IP can provide TDM level of robustness and high availability. It is undeniable that a lot of resistance happened against the migration to IP, which pushed the Telco IP implementation to be as solid and as robust as possible to match the quality requirements.
The booming of Data and Video (non voice)
The proliferation of mobile broadband world-wide the push the data traffic to increase exponentially. This is fueled by many factor such as social networks, handset capacity, 3G services, etc. This phenomena leaves Telco in difficult situation s:
- the data (non voice) traffic increased significantly that requires more bandwidth and associated infrastructure
- but, the revenue from the data does not commensurate the traffic
While the Telco still rely on voice traffic as the major part of their revenue components, the Telco operator has no choice to the data part. Despite data revenue typically are still small, they have to cope with it like it or not. Thus, they are forced to optimize the investment on infrastructure to support data and at the same time maximize the effort to monetize the data services.
The optimization of the data services now force the Telco to leave the luxurious router specification they used in the past. They now become as budgetary constraint as ISP when dealing with router investment. The correct responds from the vendor now is to create more affordable line card or model that will fit with this new requirements. The line card scale limit is pushed down and the price is becoming much more affordable now.
There are many approach by the telco to accommodate this growth. One of the approach is to put investment on the growing part which is the data. In this way, the Telco split the network to accommodate the data and the network to accommodate the voice. While the data part comes with less stringent requirements, they can safely choose less powerful line card for this purpose.
In summary, there are transition happens inside the Telco networks to match their new growth and data services. This transition as if merge the ISP and Telco design in terms of line card requirements. We are not talking about the LTE yet, still 2G/3G networks but still this part design transition should be addressed properly to improve overall service offering to the customer.
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