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i'm going to use one of crystal, cs8900a, it's easy to use, and it has a interface to the ISA bus. i'm going to use it in my proyect for inteconnecting devices via internet. There are another chips ypu can find from National, Realtek ( i think)
I don't remember seeing a ASIC to do the connection.
I am assuming that you are wanting to create either a VIOP bridge (voice) or data bridge (probably HDLC over E1).
If you are doing a voip bridge, then you will want to do some processing on the voice samples. If this is the path you are following, I would suggest a TI DSP. A 54X series is designed to provide a low cost gateway. If I remember correctly, most E1/T1 framers will connect directly to the DSP. The problem then becomes the eithernet connection. Most people then use a dedicated processor to control the IP stack. The DSP is connected to the HOST processor using the DSP host interface. There is software available for this kind of solution. If this is what you want to pursue, let me know, I can recommend some vendors to talk to. For a host processor, I would look at the MPC860 from Motorola. Already has eithernet built in and some support for E1/T1 highway.
If you are doing a data bridge, then I would would also suggest the MPC860. The part has built in HDLC and eithernet controller.
As for an E1 framer, look at Dallas semi also. They came out with an E1/T1 framer recently that used the same magenetics for both protocols. This would allow for a single design to be used for both standards (if needed).
Hope this helps some. PM me if you need more details.
my_garden, I mean that Realtek RTL8019AS and Zarlink (Mitel) MT9075 U can easy find and bye... Data sheets are also available... APP Notes and so on... :lol:
But you must work more on this project :roll:
I don't know, why you are interesting from RJ0XX...
I didn't read the data sheets, but what you think about
a chip, which manufacturer don't produce it...
First my opinion is that it's a SHIT...
I'll say you a similar example with me...
I had a device with a chip HC4 PCI-to-ISDN Controller
from HiNT before 1 year... Before some months I found
their site and noticed, that there aren't .pdfs for HC4
There are only info about their new products...
I mean HB4 family (misc PCI Bridges)... I wrote a e-mail
and they told me, that it's a old chip, which they don't
support, and they hadn't data sheets...
BUT what's happen... I have a device with their HC4,
and they havn't data sheets... What is this shit?
Huh... The situation is similar!
BTW, now I'm thinking about a project, which I can
describe as Ethernet_To_E1_bridje. This is not easy
project, you know! There aren't universal and perfect
converter! And Ethernet To E1 is very relative term...
The device can works as a special router with own
MAC address and IP, or only converter from Ethernet
1. In first case the device must do Network
Address Translation. The device must recognize
IP, TCP, UDP, ICMP, ARP and RARP packets and modify
it, not only for NAT, but to change TTL and so on...
It's not a big problem, but...
But what do you think about ARP requests? What do you
think will happen, when you have 100mbps Ethernet and
2mbps E1 with speed ratio 50:1? huh...
I suppose, that you want to say me: "The protocols
from the upper levels are interesting from this!
What you mean?"
2. In second case the device must convert and
transmit (receive) only Ethernet packets. Ethernet
NIC chip must work in promiscious mode and the
device must operate only to retransmit with incoming
MAC addresses. One of the difficult questions is:
"How long is buffer lenght? Case with 1 Eth packet
is not best, coz you will have many lost packets.
buffer with lenght 1GB is not perfect, coz you
will have terrible performace if there are hackers
or flooders... I can't say how long buffer must be...
Similar problems are examined in
<telecom-traffic_designing>... blah... blah... blah...
The device <Eth 2 E1> must support flexible
configuration, coz some devices in telecom way can
modify the flow... DEvices as digital switch and so on...
can modify not only 0 and 16 timeslots... blAH... blah..
So... you'll spend a lot of your time for this relative
But it's great to use telecom network and all telecom
equipment to make large LAN. I mean LAN, not WAN or
I don't offer you Mitel or Realtek. I wrote them for
example... I can find and buy Mitel (now Zarlink) MT9075
and have some pcs RTL8019AS. All devices from Realtek are
not best Eth NIC. But you can order and buy them...
I think that Mitel is one of well known manufacturer
in PDH Telecom area, in SDH and SONET may be Ubicom
and some others os the best... ))
Thank you very much! wzdreamer.
You give me some important advices.
Yes I have the same feel like you have.
True if I want put one 100M or 10M IP data into several E1 time slot, there are so many problem. I need a very long buffer. My god I can't know what's the best length.
If we want to decode the IP protocol, it's a very difficult work. So we must use some decode IC.
For E1 signal, I think it is easy to do. I use the Conexant's BT8370. Then I use one Xilinx's cpld do the time slot work. This part is already work well.
Now I'm thinking about how to manage the IP data.
I don't know how this project will be.
Your Device must process not only IP... You must modify all TCP packets... and UDP and ICMP and so on... This is if your device will works as a Router with 2 interfaces ) If This is only Converter to expand your network... - You must process only Ethernet packets... It's not so difficult... MTU = 1.5K aprox with PAD... ))))
I don't know what is this chip (Conexant), and will see... )))
I'm working with Conexant BT878 (Video capture) and I'm not pleased from it... This is low-cost and shit-le chip ))
You are correct SMSC's chips are not NE2000 compatible. If this is a problem OK. But having used both SMSC and NE2000 devices, I can say that it is easier to write low level routines with SMSC's chips. Anyway, choose according your specifications and experiences.