MTP2 Performance Improved

The Xyganda MTP2 has been under development (off and on for the past year) for migration from user space to kernel space to improve real-time performance. Sangoma engineering has been an intergral part of this effort by providing an efficient interface to DS0 bitstreams and incorporating MTP2 kernel module installation into the Sangoma driver installation toolset.

Recent tests in a major equipment vendor's lab revealed a kernel panic which was the result of the xmtp2km kernel module not supporting SMP environments. Redesign of local buffer allocation tools within xmtp2km eliminated some access contention situations, while other access contentions that could not easily be eliminated were streamlined and protected with spinlocks.

The improved xmtp2km has survived a 90 hour duration test under heavy and light traffic loads with 0% message loss or gain. The next step is to distribute the fix to the field and continue observation of the fix in those environments.

One benefit of fixing the xmtp2km problem is that we learned that the interface between the Sangoma driver and xmtp2km is very efficient. The Sangoma driver allocates a large pool of buffers for managing the bitstream flows between itself and xmtp2km. We have never seen more than one buffer in use at any time regardless of traffic loading on the link. We also we able to transmit and receive an +80% load on a link for over 12 hours at a time without a single occurence of link congestion onset/abatement. A relatively weak computer (a single 933 Mhz Intel CPU) was in use which adds weight to our findings. These observations indicate that the code is efficient and that real-time requirements are being met with a wide margin of safety.

ISUP and CNAM development came to a full stop while xmtp2km was being debugged. We apologize for the delays in the ISUP and CNAM projects and will resume development on these applications immediately.