Bong-Tae Kim

A multi-gigabit rate deep packet inspection algorithm using TCAM

With the increasing importance of network protection from cyber threats, it is requested to develop a multi-gigabit rate pattern-matching method for protecting against malicious attacks in high-speed network. This paper devises a high-speed deep packet inspection algorithm with TCAM by using an m-byte jumping window pattern-matching scheme. The proposed algorithm significantly reduces the number of TCAM lookups per payload by m times with the marginally enlarged TCAM size which can be implemented by cascading multiple TCAMs. Due to the reduced number of TCAM lookups, we can easily achieve multi-gigabit rate for scanning the packet payload. It is shown by simulation that for the Snort rule with 2,247 patterns, our proposed algorithm supports more than 10 Gbps rate with a 9 Mbit TCAM.

Efficient dynamic bandwidth allocation for FSAN-compliant GPON

We suggest an immediate allocation with colorless grant (IACG) method for dynamic bandwidth allocation of a gigabit passive optical network (GPON) system. The suggested method is based on the GigaPON Access Network (GIANT) media access control (MAC) method. The IACG method can assign the transmission bandwidth regardless of the value of a scheduling counter, whereas the GIANT MAC method can assign the transmission bandwidth only when the scheduling counter has a value of 1. Also, unlike the GIANT MAC method, the IACG method utilizes the unallocated remainder of the transmission bandwidth. At the end of scheduling, the IACG MAC method assigns the unallocated remainder to each optical network unit (ONU) with an equal share. Using computer simulations with the self-similar traffic model, we show that the IACG method dramatically outperforms the GIANT MAC method in mean delay and frame-loss rate.

A WDM-Ethernet hybrid passive optical network architecture

The wavelength division multiplexing-passive optical network (WDM-PON) has been known as the utmost advanced technology with high security, guaranteed QoS, transparent protocol and so on. However, WDM-PON is too expensive for general users, and its bandwidth is too much for the present services of individual general subscribers. This paper introduces a hybrid PON based on WDM, namely WDM-Ethernet PON (WE-PON), in which WDM-PON is integrated with time division multiplexing PON (TDM-PON) by AWG and splitter. WE-PON with 32 branch splitter can get down very close to that of TDM-PON. It can significantly lower the out side plant cost as well as maximizing the fibre utilization

A Hierarchical Weighted Round Robin EPON DBA Scheme and Its Comparison with Cyclic Water-Filling Algorithm

A H-WRR (hierarchical weighted round-robin) EPON (Ethernet passive optical network) DBA (dynamic bandwidth allocation) algorithm is devised and investigated. WRR table entries having reports are scanned to generate the gate which is limited to the token size of the entry. LLEDs (logical link IDs) are grouped into classes and maximum delay control is provided per class and minimum idle state polling rate is configurable for each ONT (optical network terminal). The schemes bandwidth allocation behavior and delay performance are shown through VHDL simulation with highly random self- similar traffic and comparison is made with previous CWF (cyclic water-filling) DBA (Kim et al., 2005). We conclude that in general, WRR DBA outperforms cyclic DBA and the H-WRR DBA scheme provides very low delay and high throughput.

Design and Implementation of an EPON Master Bridge Function in an ASIC

An EPON(Ethernet Passive Optical Network) master, slave chipset was developed. In EPON, LLID(Logical Link ID) value in the Ethernet frame’s preamble is used to make the PON look like a point-topoint links seen from the OLT(Optical Line Termination) and ONUs. This paper describes the functions and implementation of an EPON bridge in the master chip which performs bridge function for the upper network port and many lower PON logical ports differentiated by LLID. This bridge also has VLAN(Virtual LAN)-LLID mapping function to make the PON appear as many VLANs seen from the network port. It is also possible to define many VLANs for each ONU. It also has multicast pruning function through which only registered multicast traffic is sent downstream to destined ONUs.

Highly efficient, wavelength-selective out-coupling of cladding mode using tilted fiber grating and micro-etched cladding

A highly efficient, wavelength-selective detection through micro-etched groove on cladding of tilted fiber gratings (TFGs) is proposed and experimentally demonstrated. More than 88% power of the cladding mode is out-coupled into an optical power detector

Minimum Credit Method for Dynamic Bandwidth Allocation in EPON

We suggest a new minimum credit method for the dynamic bandwidth allocation in EPON. In the suggested method, to eliminate the unused transmission time-slot, each ONU requests no more than a predetermined maximum. We analyze the upstream channel resource wastage when traffic is light. Based on the analysis, we derive a minimum credit that eliminate the upstream channel resource wastage. The OLT estimates a traffic load and grants a minimum credit when the request is smaller than the minimum credit and traffic is light. Using simulation, we show the minimum credit discipline is superior than the existing methods in the mean delay and the frame loss rate.

An Improved Cyclic Water-Filling EPON DBA Providing Priority Scheduling and Faster Allocation Time

A cyclic water-filling EPON (Ethernet passive optical network) DBA(dynamic bandwidth allocation) algorithm and its implementation in an ASIC are described with future improvements. Every cycle, short static gates are generated to collect reports and dynamic gates are generated according to the reports collected in previous cycle. In each cycle, unit length is additively allocated to the ONUs in a cyclic fashion until all the requests are satisfied or no resource is left. Four parallel engines are used to process the requests. As improvements, priority will be considered, and the processing burden will be evenly distributed to the 4 parallel engines in any case.

FTTH-based IPTV testbed in Korea

The IPTV service is a worldwide trend, however it has been delayed in Korea. ETRI has been building own FTTH service center connected with commercial FTTH networks. We describe the architecture and related technologies.

Bi-directional ONT Module for Asymmetric 10Gbit/s PON

We have developed the first bi-directional ONT transceiver module having 10Gbit/s-Rx and 1.25Gbit/s-Tx for asymmetric high-speed TDM-PON, and have confirmed the 10Gbit/s downstream performance with the bi-directional transmission to support 128-way split and 10km reach.